Secret Agent "X" – The Complete Series, Volume 2

Chapter I

A FAST roadster came to a skidding stop at a spot where shadows lay like huge, ungainly serpents across the gray surface of the city streets. A tall man leaped out. He closed the car’s door quickly, moved along the sidewalk with swift, silent steps.

Walking the length of one block, he turned left down another, slowing when he reached a bright corner light that was holding at bay the night’s curtain of chill darkness.

Opposite this light, the big marble front of the Union Bank Safe Deposit Company rose in glittering magnificence. A special guard in horizon blue was on patrol duty here. The guard turned once, glanced at the lone pedestrian, turned away.

There was nothing about the man’s appearance at that distance to stir suspicion. He was quietly dressed in a gray suit and topcoat. Neat, respectable, middle-aged, he looked like some late office employee, a bookkeeper perhaps, hurrying home from work.

But the instant the guard turned a corner of the building to patrol its north side, the gray-haired man crossed the street and approached the bank’s heavy doors.

He pressed his body into the vestibule, took something from an inner pocket of his coat. This was a small leather case containing an assortment of complicated, strangely shaped tools of the finest chromium steel. Some were straight and slender like darning needles. Some had elaborate goose necks. Others had tiny pivotal extensions.

The man used them with amazing speed and dexterity. Before the bank guard returned to his west side beat the man in gray had opened the building’s outer doors and slipped between them. Another set of inner doors faced him.

Now the man in gray drew a flashlight from his pocket, working with still greater care. By attaching a small steel tape to hidden terminals, to insure an unbroken circuit when the doors were opened, he disconnected the sensitive alarm system which protected the bank. Then he used the tools again, probing the secret of this inner lock as he had the first, and entered the bank.

The glow of a single overhead night light sprayed dim radiance on his face. The features of that face were blunted, inconspicuous. But the eyes blazed with a strangely intent, strangely compelling light. They flashed intelligence, magnetism, power, that seemed incongruous to those prosaic features. They suggested that this tall, gray-clad man who had so unceremoniously entered a great banking institution of the city was a figure of force and mystery. They gave the only clue to his identity as one of the most daringly ingenious criminal investigators in the world.

For the gray-clad man was Secret Agent “X,” master of a thousand faces, genius of disguise, pledged to ceaseless warfare against the destructive forces of the underworld.

ONCE again this man whose real name and identity had never been revealed, was following what appeared to be the black shadow of vast, organized crime. Once again he had become an apparent outlaw in his efforts to track down the lawless.

The trail he was following tonight was dim, indefinable as yet. Certain things had made him suspicious. Certain whispers had reached his ever-alert ears. A series of crimes had occurred in many States. They were so perfect, so efficiently worked out in every detail that, to the mind of Agent “X,” they betrayed the stamp of a single master hand. Menace that was nation-wide was reflected in them. Menace like dread, poisonous tentacles reaching out toward many states. Now, true to a pledge he had made to an official high in Washington’s governmental circles, Secret Agent “X” was investigating.

He crossed the lonely interior of the bank on his rubber-soled shoes. He passed the barred windows of the cashiers’ cages; passed the neat desks where the bank’s officials sat in the daytime, moved on toward a stairway leading down to the safe-deposit vaults.

It was in one of these that the Secret Agent’s interest lay. Its contents might reveal or conceal evidence of the strange, dark thing he suspected. If he were right in his suspicion it would send him out to do battle again with the underworld — to fight a wave of terror that threatened to become a veritable juggernaut sweeping and crushing all before it.

At the bottom of the stairway a steel grille rose from floor to ceiling. There was a locked door in the center of it. Behind this was a small room with a desk used by the man who kept the vault records. At the other side of the room was another grille of inch-thick bars, protecting the safe deposit vault where tier upon tier of locked metal boxes gleamed dully. A small bulb burned here also. It was strangely like looking into the mouth of some subterranean hell. The bars made distorted shadows. The metal strong boxes reflected weird lights. The breathless quiet of the huge bank building seemed ominous.

A slender, goose-necked bit of steel in the Agent’s skilled fingers probed the lock aperture in the first grille. The bulb in the vault beyond gave him sufficient illumination. He did not need to use his flashlight. But suddenly, as though some evil thing had breathed on it, the bulb in the vault went out.

The Agent tensed. His hand with the small metal tool in it paused. He waited in absolute darkness. Was this some part of the bank’s alarm system that he had overlooked?

He pocketed his tool, crept cautiously back up the marble stairway to the floor above. The overhead bulb here had gone out, also. The whole great building was utterly dark. He glanced out one of the bank’s barred windows. The corner street light had also been extinguished.

Then Agent “X” heard a noise. It came from beyond the bank’s front doors. It was a single muffled cry; weird, disturbing — a cry of human agony. Agent “X” leaped toward the door, stopped. There was a sound here, too. It was a strange hissing noise, like air coming through some constricted escape — or like the hissing of some giant reptile. It increased each second, seemed to be coming nearer and nearer.

The Agent’s scalp tingled with excitement, curiosity. Fear he had long ago cast out. It had no place in his perilous work with the threat of death always present. But, for good and sufficient reasons, he did not want to be discovered here.

He stepped through the swinging gate into the section set apart with a low partition for the bank’s officials. He crouched behind a desk, stared tensely at the door, listened to that odd noise, trying to identify it. Then he understood.

As though the hiss were a dragon’s fiery breath upon the door, something glowed there, something inhumanly bright. It crept around the lock that Agent “X” had so deftly picked with his delicate tools. It ate a hungry circle in the very metal of the door itself, cutting the lock out of its setting. It was the greedy flame of a white-hot torch. Some one was breaking into the bank.

EVERY muscle taut, Agent “X” waited. He had come to the bank to trace down if possible the source of a hidden menace. Now that menace was manifesting itself dramatically, making its presence felt even before he had accomplished his purpose. The Union Bank Safe Deposit Company was being raided by bandits who worked in the dead of night with amazing skill and speed.

The lock of the door dropped inward with a metallic clink. The heavy door swung open. It seemed to Agent “X” that the darkness of the street outside disgorged at least a dozen masked figures. They entered swiftly, soundlessly. One clicked on a flash. The two nearest to “X,” silhouetted against the hand light, looked like crouching monsters.

“X” saw then that one of them held a sub-machine gun. The man’s finger was crooked like a talon through the blued trigger guard. The wicked snout of the weapon was longer than that of any machine gun muzzle “X” had seen.

A powerful flashlight swept the interior of the bank, settled on the gleaming, clocklike face of the great vault where the bank’s cash assets were kept. One of the bandits barked an abrupt order.

The Secret Agent took his gas pistol from his pocket. He seldom carried lethal weapons. The gun in his hand was effective within a radius of twenty feet. It could knock a man unconscious, swiftly, silently. But it would be futile against a stream of bronze-jacketed machine gun bullets.

The Agent had other defensive equipment. He wasn’t afraid. He waited, trying to see the faces of these men, wondering how they would go about the opening of this great vault with its ponderous mechanism and time-lock.

One of them was bringing forward an elaborate gas torch on rubber-tired wheels like a movable tea table. This was the same implement that had eaten so readily through the heavy bronze doors. “X” saw at once that it was no ordinary acetylene torch. Huge cylinders of super-compressed air whipped the gas at its outlet end into crucible heat. He got a whiff of the gas itself, realized that this was no calcium carbide product. Here was something new.

At a low-voiced order, the man operating the torch pressed a lever. The dazzling jet of flame leaped out. Agent “X” was amazed at the ease with which it ate into the vault’s molybdenum steel. They were attacking the time-lock itself. As though it were hardly more than solder, the tempered steel melted away. The man at the torch’s end wore a mask to protect his eyes. It gave him the look of a devil.

There was no question now that they would succeed in their plan. Here was another of those devilishly ingenious crimes — a link in that chain that Agent “X” had sensed. Here was a group of the very criminals he had set himself to fight. He couldn’t stand by and watch them loot the vault of hundreds of thousands. For once, it was a situation when he could logically summon the police.

Stealthily, “X” edged around the desk, crept toward the door. With the bandits preoccupied over the vault he hoped to leave unseen. But hardly had he moved when a guttural voice sounded in the darkness against the wall at his left. One of the bandit gang had been stationed inside as a guard. The bright beam of a flashlight swung toward Agent “X.” A hoarse order was given.

From the snout of the sub-machine gun in the crouching bandit’s hand a flicker of greenish flame spewed forth. There were no sharp reports. Only a series of dull pops. The gun was silenced — the first of its kind “X” had ever seen. But even as he tried to leap aside, there came the sickening smack of bullets striking him. They beat a weird tattoo against his chest. He staggered, clawed at the air a moment, while breath whistled through his teeth. Then he collapsed on the floor and lay still.

Chapter II

THE bandit with the gun ceased firing abruptly. He and the man with the light walked over to the spot where Agent “X” lay. The gunman gave the inert body a vicious kick. He turned “X” over on his back, stared down.

There was no indication of life. It seemed certain that no living thing could have withstood that hail of merciless, bronze-jacketed lead. The gunman grunted, spat, moved back to his position by the wall. The man with the light walked close to the vault. The killing of a human being was only a minor incident to these men.

But Agent “X” wasn’t dead. When the hail of machine-gun bullets had struck his chest it had seemed that someone was delivering a series of sledge-hammer blows close to his heart. He was wearing a bullet-proof vest — one of the most ingenious in existence. Two shells of metal, the inner one hardest manganese steel, the outer one bronze alloy, with an insulating stuffing of raw silk between.

Even bullets fired at close range couldn’t puncture that inner shell. But the concussion of the sub-machine gun pellets fired so closely had battered him into unconsciousness. They had gone through the outer bronze alloy covering of the vest, buried themselves in the raw silk, flattened noses pressed against the inner shell. The holes in his clothing showed plainly. He was unconscious. It was natural for the bandits to think he was dead.

He lay helpless while they succeeded in burning the time-lock mechanism of the great vault. They swung the ponderous door open, stuffed hundreds of thousands of dollars into canvas sacks, withdrew from the bank like a pack of slinking gray volves. A high-powered car purred outside. Gears clashed. The car sped away into the night….

Agent “X” stirred. Another sound had cut through his dazed consciousness — the persistent wail of a police siren, coming nearer and nearer. No sooner had the bandits’ car left the bank than a small, bright-eyed man who had been watching outside went to a drugstore telephone down the block. He sent in a hurry call to headquarters. He was a notorious police stool pigeon, an underworld rat named Clawdon.

As the sleek police cruiser roared up to the curb, Clawdon leaped on the running-board, spoke hoarsely.

“I just seen a gang of guys leavin’ the bank, chief. They must a done a job on it. I was down the block and seen the light here go out. Then I heard some one holler and came as fast as I could.”

A cop leaped out of the car and swore harshly as he stumbled against something and almost fell. The bank guard, his horizon-blue uniform sodden and stained with crimson, lay on the sidewalk. He had been callously left there by the bandits, the back of his head smashed in by a vicious blow.

“Geez! They moidered him,” screamed the stool pigeon.

One of the cops sent an emergency call into headquarters. The other went into the bank, with Clawdon, the stoolie, at his heels.

Agent “X” dimly heard the thud of their feet. But he was still too dazed to move. The awful hammer beat of those bullets had almost paralyzed his body.

He did not open his eyes until a second and third police siren cut hysterically through the air. A half dozen headquarters cars were converging on the raided bank. When Agent “X” became fully aroused to consciousness a group of harsh-faced cops were standing above him. One was prodding him with the end of a nightstick.

Clawdon, the stoolie, was staring down in bright-eyed speculation. As Agent “X” rose to a sitting position, the stoolie slipped out of the bank unobtrusively and disappeared along the night-darkened street.

A BIG man with a pale, aquiline face and black eyebrows that jutted menacingly above cold, piercing eyes shoved through the group of cops. He was Inspector John Burks, head of the city homicide squad. Murder as well as robbery had taken place. Burks, dealer in death, was on hand.

A grim smile twitched the corners of Agent “X’s” mouth. The man above him was one of his worst enemies on the force.

Burks stooped down, laid his hand not too gently on the Agent’s shoulder.

“What’s your name?” he challenged.

Before “X” could speak the inspector’s piercing eyes had detected the bullet holes in the front of the Agent’s coat. “Good God! This man has been shot a dozen times. Call an ambulance!” Then his face hardened, his fingers pawed the cloth.

“Wait. We don’t need an ambulance. He’s wearing a bullet-proof vest. He’s O.K.”

The words had a startling effect on the men around. They tensed. Agent “X” could feel their eyes boring into him with piercing suspicion. One, a sergeant of detectives, spoke harshly!

“I’ll bet he’s one of the gang, chief. Maybe they tried to knock him off so he wouldn’t squeal.”

The inspector thrust his jaw close to the Agent’s. “Speak up — who are you and what are you doing here?”

Agent “X” was silent a moment, then he waved his hand toward the opened vault.

“That’s more important, inspector. Find out who robbed this bank. I happened to be here when the gang came in. I was going to call the police; but they shot me down before I could do it. This thing I’ve got on wasn’t built to stand machine-gun bullets.”

He was fencing for time. He knew he was in a tight spot. The secret of his identity must not be uncovered.

“You happened to be here!” barked Burks. He reached forward, located the Agent’s gas gun, jerked it out. “You happened to be carrying that, too, I suppose, and wearing that vest!”

A slow smile overspread the Agent’s disguised face. He took a card from his pocket, presented it to Burks. It bore the name: “W. T. Garrison, Investigator, American Bankers Association.” Prepared for any emergency, he had even anticipated the possibility of being caught and questioned. But Burks did not seem satisfied. He fingered the card, continued to glare at “X.”

“If you saw these men,” he said, “maybe you can give a description of them. Who were they and how many were there?”

Agent “X” shook his head. “I couldn’t see their faces. There were a half dozen, I should say. I never saw them before.”

“You couldn’t identify them in court if they were arrested then?”

“No.”

Burks stabbed a finger at “X.” “It looks funny, Garrison. Private investigators don’t wear vests like that one you’ve got on — and they don’t happen to be around when robberies are being pulled off. More likely you’re in with the guys who did this, and they double-crossed you because they thought you’d squeal. You expected it might happen and got dolled up in that vest.”

Burks turned to two of his men. “Take him down to headquarters, boys. Hold him there till we’ve had time to investigate him.”

A big detective marched “X” toward the door. Two cops moved up on either side of him, guns in their hands. Burks rasped another order.

“Keep a gun at his head. That’s one spot bullets can reach.”

The cops obeyed, seizing the Agent’s arms. An electric company truck was replacing the light outside. A sizeable crowd had collected. They goggled at Agent “X” with curious eyes. A half dozen police were strung along the curb.

He let himself be shoved into a big headquarters car. This wasn’t the moment to attempt a get-away. But he had no intention of going to a cell in the station house. Many times the police had tried to arrest him. Many times they had failed. In a prison cell his usefulness as a criminal hunter would be thwarted. To save himself from this he carried many unique defensive devices in the inner linings of his coat.

The police car leaped away from the curb. A cop and a plain-clothes man flanked “X” on either side. The other cop drove.

“How about a cigarette?” the Agent asked casually, but the detective shook his head.

“You’ll have plenty of time to smoke down at the station house.”

“X” smiled grimly again. They had denied him the use of his special gas-filled lighter, cut off one avenue of possible escape; but there were many others. His fingers crept up to toy with the innocent looking fountain pen that reposed in his coat pocket. The cop who was driving gave a sudden exclamation.

“What do those guys think they’re doing?”

AGENT “X” stared ahead over the driver’s shoulder. Through the glittering windshield he saw a large and powerful black car lurch past and cut in ahead. The car stopped suddenly with a squeal of brakes.

The police car’s driver jammed on his own brakes, narrowly averting a crash. He was swearing now; but his curses ended in a surprised intake of breath. For three men had leaped from the car ahead. They were masked, and they carried guns in their hands. One was a sub-caliber, rapid firer.

Agent “X,” tense with excitement, recognized the gun as the same used on him in the bank. Its muzzle held the cylindrical silencer that reduced its reports to mere pops.

One of the masked men approached and spoke sharply.

“We want that guy you got. Hand him out!”

Dazedly the detective on “X’s” left opened the door. The cop started to lift his gun.

“Cut it!” the masked man snarled. “You’ll take a one-way ride to hell if you don’t. We got a typewriter here.”

This was gangster talk. The cops’ faces froze. A masked man reached forward, grasped “X” by the arm.

“Come on, feller, make it snappy.”

He was hauled out of the police car. His eyes were bright with excitement. These men had left him for dead. Now, learning that he was still alive, they had come back for him. Some one had tipped them off. Death glared from the muzzle of the machine gun aimed at his head. Another of the masked men pressed his automatic against Agent “X’s” neck.

“No funny business, or you get it sure.”

He was marched forward toward the other car which waited, its engine running. The man with the machine gun covered their retreat. Agent “X” was thrust into the big, closed sedan.

Then the cop who was driving the police cruiser ducked behind his dashboard and cut loose. Agent “X” admired his nerve. The blue coats had courage all right.

But the vicious, muffled thudding of the silenced machine gun sounded. “X” heard the slap of bullets against the police car’s windshield, followed by the gasping cry of a wounded man. Another burst ripped the headquarters car’s tires; made its engine hiss to a clanking stop. The machine gunner leaped into the sedan. Its door slammed shut. The sedan spurted away up the street, powerful engine roaring.

Chapter III

THEY did not speak until the car had covered several blocks. Then the man holding the gun to the base of “X’s” brain ordered abruptly:

“Take off his coat and that damned vest!”

This, too, hinted at a cold intent to execute him. “X” waited, measuring his chances of escape. They were slight at this moment. For the man with the sub-machine gun sat facing him, straddling one of the sedan’s small, collapsible seats. The snout of the rapid firer was inclined toward his face. A slight pressure on that curved trigger and his head would be torn to pieces.

The gangster on “X’s” left peeled off the Agent’s coat, unsnapped the fastenings of the bullet-proof vest. He removed the vest quickly. The muzzle of the sub-machine gun pointed straight at the Secret Agent’s heart. For once he was utterly helpless, his life suspended by a slender thread.

He could not see the men’s faces. They still wore their masks. He knew that these were not the only ones who had robbed the bank. The others must be somewhere ahead in the darkness.

One of the men held up the vest that had saved the Secret Agent’s life.

“Some gadget,” he remarked. “I never seen one like it before. We’ll have a bunch like this made.”

They did not question “X.” That surprised him. But abruptly one of the masked men took something from a side pocket of the car. It was a roll of strong adhesive tape. He gave an order.

One of the men held “X’s” wrists while the snout of the machine gun pressed ruthlessly against his flesh. There came the ripping sound of tape, the coolness of it against “X’s” skin. They were taping his eyes so that he could not see. Another strip was pressed firmly across his mouth.

The big car roared on, the men in it silent for the most part. Once “X” heard the thin, complaining note of a police cruiser’s siren far behind. The sedan turned sidewise, moving off at a tangent from the course it had been following. The police siren’s note faded out.

Agent “X,” his masterly sense of direction vividly alive, took note of each turn made. The hollow sound of the street crossings came plainly to him. He counted them. After a time he felt the car moving at an upward incline. There came the rumble of a long bridge. He had crossed every bridge into the city many times. Each had a different angle. This one was familiar.

The complicated route that the car took after leaving the bridge didn’t entirely confuse him. When it stopped at the end of nearly forty minutes, Agent “X” could make a guess at its approximate location.

It nosed over bumpy ground — and to “X’s” keen ears came a new sound. This was identifiable, too. It was the low, distinctive hum of airplane motors.

He listened carefully as the sedan’s door opened. The motors were synchronized. They were all on one plane; three of them. A big, tri-motor ship was warming up. He was at some hidden airfield at the outskirts of the city.

His pulses tingled. Here was more evidence that this was a huge, well-organized group.

Cool night air beat against his face. Mingled with the popping rumble of the plane’s warming motors came low-voiced orders, the crunch of footsteps. The sub-machine gun’s muzzle pressed firmly against his spine. Two men grabbed his arms, pushing him roughly forward.

THE beat of the tri-motor’s engines deepened. He could hear the swish of the idling propellers now, the click of the valves. Metal grated directly ahead of him. He was lifted, thrust into a small space which he identified as a compartment in the tail of the big plane’s fuselage. There was sheet metal all around him now. The pressure of the machine gun and the clutching fingers were withdrawn. Agent “X” was a prisoner in the body of a big plane about to take off in the night to some unknown destination.

He waited till the throbbing rumble of the plane’s motors deepened into a vibrant roar; waited till he felt the huge craft moving forward for the take-off. Then, in the stuffy darkness of the compartment where he had been thrust, his fingers went to work.

He peeled the tape from eyes and mouth, flexed his cramped lids and lips. No slightest ray of light penetrated the narrow compartment imprisoning him. It was windowless, ventless. The only air was that which seeped in around the edges of the door. It was a baggage compartment in what had once been a passenger air liner.

The sheet metal around him was vibrating now with a steady motion indicating that the great plane had taken off, was rising upward into the night sky.

Putting his ear close to the metal ahead he detected the faint sound of men’s voices in the cabin. He reached into his pocket and made an unpleasant discovery.

His pockets had been emptied. Everything had been taken out: wallet, keys, knife, and chromium tools. His tubes and vials of makeup material were gone. His captors had removed even the small, portable sound amplifier which had so often stood him in good stead.

But one thing the gangsters had overlooked — not knowing yet with whom they dealt. In the sole of the Secret Agent’s shoe was a combination file and hacksaw, its blade made of tempered steel and a strip of glass-thin black diamond set in special cement.

Before removing this from its hiding place Agent “X” felt along the walls and ceiling of the compartment. It was made of soft, lightweight corrugated duralumin, riveted together. By pressing against the metal which was hardly thicker than tin, he located the points where it was fastened to the framework of the big fuselage.

Then, his face keenly intent in the darkness, he took the implement from his shoe and set to work. He punctured the duralumin floor with the point of the instrument. The razor-thin blade sliced through the metal as “X” drew it back and forth. The roar of the plane’s engines covered the faint, rasping sound it made. He worked with energetic speed. No telling how soon the plane might land — though at the moment it seemed to be climbing steadily. The pressure in his ears told him it had already reached an altitude of several thousand feet.

He made parallel cuts in the metal floor of the compartment, then cut crosswise at top and bottom and took the panel out. A space was disclosed beneath his feet. He reached down, groped in the darkness with tense fingers. His hands encountered a metal cable that moved snakily beneath his touch. It ran through pulleys that had pivotal fastenings. There was another cable at the other side of the hole he had cut. These were the plane’s controls, going to rudder and elevators.

AGENT “X” worked with his hacksaw again. He cut out another panel in the compartment’s flooring, as far forward as he could. Then he sawed several narrow strips of duralumin, tapering the ends. The thinnest strips could be used like flexible wire. They would suit his strange purpose nicely.

He put his hacksaw away temporarily and hunched forward, bracing his knees. He judged that the plane had left the city far behind now. Below must be a stretch of small towns and open country. He took a grip on the cable of the elevator control, wrapped his fingers around it, suddenly pulled with all his might.

The abruptness of the maneuver drew the control away from the pilot’s grasp, made the big plane’s nose dip down — and Agent “X” shoved a strip of metal between the cable and one of the pulleys, wedging it in.

The plane had now gone into a steep dive. He wrapped a strip of the duralumin around the cable and the pulley, holding it in that position. The quick tugs on the forward section of the cable indicated the pilot’s frantic attempts to free the controls and right his ship.

Agent “X” left him no time to recover. He seized the rudder cable next; jerked on that as he had on the other, felt the big plane swing its nose around. It heeled over on one wing, threatening suddenly to go into a deadly flat spin, and again Agent “X” wedged the control so that the pilot up forward was helpless.

The Secret Agent sat back on his heels, waiting tensely. The pitching and rocking of the ship threw him off his balance, hurled him against the wall of the compartment. The engines were cut down for a moment as the pilot sought desperately to free his wedged controls. Above the rumbling pop of the idling motors and the rising sigh of wind in the wings, Agent “X” heard the shouts of excited, frightened men. He heard stumbling feet up forward, heard a crash as a loosened seat or table struck one wall.

The great plane careened, did a falling leaf maneuver; hung for an instant dizzily. Then it slid off on one wing, plunging toward the earth far below, as though all the fiends of destruction were driving it down to its doom.

Chapter IV

IN the rocking, shuddering compartment of the plane’s fuselage, Agent “X” thrust his feet through the holes he had cut in the flooring and braced himself. The tail assembly thrashed from side to side as though the ship were a plaything of gigantic forces.

“X” heard the rising voices of men in the cabin. One of them screamed in terror. Thudding sounds pounded above the vibrating whine and mutter of the motors. Some one shouted an abrupt command.

Agent “X,” every muscle in his body taut to avoid the danger of being pitched against the metal walls, took out his hacksaw again. Quickly he cut a hole through the thin sub-flooring of the compartment A spurt of night air, chill as ice water, struck his face. But below, all was darkness.

He bent down, gripping a tubular steel brace, adjusting his eyes to the air blast that increased as the ship dropped.

Suddenly a brilliant flash of light stabbed upward. After the utter darkness inside the compartment, it almost blinded him. It was as though the night flamed with purple fire.

The light continued. It was the livid glow of a landing flare dropped by the pilot of the plunging plane. Agent “X” saw terrain then — fields, fences and clumps of trees far below. Here and there the square dot of a house showed, with smaller dots that were outlying buildings. These were farms. They were over open country.

The plane, utterly out of control, yawed sickeningly, great wings fanning the air, tail sweeping from side to side. The shouts of the men up forward rose in a frenzy of terror.

Abruptly Agent “X” bent lower, staring down through the rent in the metal. Something like a circular white flower blossomed beneath the ship, starkly outlined by the landing flare against the darker countryside. It was an opening parachute. One of the plane’s passengers had jumped.

Another and another chute appeared as “X” watched, a grim light of triumph in his eyes. He widened the hole in the flooring with quick, tense thrusts of his hacksaw to open up a fuller range of vision. He counted the chutes as they blossomed out till twelve had appeared. The gangster criminals were leaving the plane, deserting it as rats desert a sinking ship.

The Secret Agent rose abruptly from his bent position. He stabbed the sharp point of the hacksaw forward, puncturing the wall between the prison compartment and the plane’s cabin.

The engines had not been shut off. They roared and moaned, changing pitch with every erratic maneuver the great ship made. When air currents, or the crazy sweep of its jammed elevators turned its nose upward, the labored beat of the steel propellers slowed the motors to a furious, complaining whine. When the nose dropped and the ship swept into a power dive, the engines, free of strain, rose to frenzied shriek as the revolutions mounted.

Agent “X” was struggling against time. He had taken a desperate chance to rid the ship of the criminals. He had gambled that they were not air-minded enough to stand for long the erratic movements of the plane. A greater fear had forced them to risk the chutes in order to escape a more certain death. But, in driving them out, the Agent was bringing destruction close to himself. For the ship was losing altitude with every sickening lunge.

“X” came to a steel cross piece in the duralumin wall head. It slowed the blade of his hacksaw. He made another cut parallel with it, sawed across the top, pulled fiercely at the metal panel. If he didn’t get through to the pilot’s cockpit and reach the controls in the next few seconds he would be smashed to a jelly in the shattered, battered wreck of the ship when it struck the ground.

Sweat bathed his body as his fingers tore the metal strip. There was a plaster-board lining beyond. That snapped and crumbled under the swift lunge of his fist; but the hole he had cut was still not big enough to get through — and the steel cross-piece was impeding his progress. He drew his hacksaw under it, sawed frantically, till the blade’s note rose above the engine’s roar.

THE plane was within a thousand feet of the ground now. It gave a sickening, forward lunge that lost another hundred feet of altitude.

Desperately he turned and bent above the floor opening. He drew the metal strips from under the jammed control cables where they passed through the pulleys. He unwound the other from the cables themselves. The cables came free. They slid through the pulleys as wind pressure forced the elevators level. The pulley wheels whined.

The ship’s erratic maneuvers ceased. It almost leveled out. But there was no hand at the controls. The plane was still a plaything of the wind and air currents. With the engines full on it began a long sickening power dive toward the earth.

Secret Agent “X” worked like a madman. There were houses below — there were sleeping humans all unaware of the great rocketing tri-motor above. What if the plane struck a building? He could vision the wild holocaust of death and destruction that would result. Hot flames searing the night landscape. Smoke like a funeral pyre.

He had cut below the steel cross-brace now. He pulled at the duralumin with fierce tugs, cutting his hands. He kicked the plasterboard lining through with lunges of his shoe. Then, at last, the hole was large enough. He stooped and shoved his head and shoulders through, drawing his body after him.

There was a deadly evenness about the ship’s forward movement now. It was like the calm before the storm. It was as though the plane, a sensate thing, had resigned itself to utter destruction.

Agent “X” rose to his feet, lunged down the aisle in the cabin between rows of empty seats. The interior of the great plane was almost as large as that of a railway car.

The pilot’s door ahead was open. A short flight of steps led up to it. Dials gleamed on the instrument panel in the glow of electric bulbs.

The plane had dual wheel controls — a mechanism familiar to Agent “X.”

He leaped into one of the leather-cushioned seats, stared through the front vision window — and his heart seemed to rise in his throat.

Directly ahead, not more than five hundred feet below, were the lights of a small country village. For a second he caught a glimpse of the main street; saw a cluster of people in front of a drug store staring up, attracted by the increasing roar of the three great motors.

The Agent gripped the wheel controls, and beneath his disguise the veins stood out on his forehead like knots. For the terrific blast of the air stream was holding the elevators and ailerons in their present position as rigidly as though they were frozen.

WITH all his might he drew back on the control, feet pressed against the rudder bars, praying that he could avert the threatening disaster, praying that he could keep the plane from plunging like a destructive meteor into that peaceful village below.

For age-long seconds it seemed hopeless. Through the shimmering arc of the middle propeller the lights of the village still showed, growing larger every instant. They appeared as steadfast as a target in a cannon’s sight. Muscles in the Agent’s arms and shoulders knotted, bulged.

Then gradually, like the bow of a ship swinging slowly up on a great swell and making the horizon line sink, the nose of the big plane began to rise.

The lighted street sank from sight. The propeller appeared to crawl up the side of a building, up, up, till the rooftop showed. The Agent gave a final, desperate pull on the wheel. The steel chains in the sprockets passing from the control wheel down to the cables were so tight that it seemed they must snap.

But the peaked roof of the building sank from sight, too. The upper branches of a tall elm tree rushed into view. The plane, almost level, hurtled through them with a sickening swish and clatter. The big steel propellers sliced leaves and twigs, sending them showering to the ground. The plane’s fat air wheels swept through the bigger branches as it lunged upward, beating the tree top with its widespread tail assembly.

The propellers caught the air, snarled with a new note. The three radial motors whined with the deep-voiced pull drone. Agent “X” fed gas to them; drew the wheel back almost to his lap — and the great plane roared upward, mounting dizzily after the tremendous momentum of its dive.

He had saved it from crashing; saved the villagers from the death that had swooped down at them out of the night sky; he had saved his own life.

But as the huge tri-motor climbed steadily into the night sky the Agent’s mind raced. He had won this round with the criminals, had escaped from an apparently hopeless trap. But his real battle was only just beginning.

When the altimeter showed four thousand feet, he left the controls for a moment and went back into the cabin. There was nothing here to identify the men who had been in the plane. They had taken the bank cash with them when they jumped. But the Agent tensed suddenly.

On a small shelf at the rear of the cabin compartment were the things they had taken from his own pockets; his make-up equipment, tool kit, amplifier, bullet-proof vest — everything. He put the vest on, thrust the other things back into his coat, went to the controls of the plane again. He banked, swung due west, and looked at the compass.

Familiar with all the terrain around the city, he could give a good guess as to where he was now. He stared out a side window. The faint gleam of river water below, a string of lights set along a highway, gave him his bearings. He identified the village he had almost crashed into. He swung the ship toward the west, followed the river for a few miles. Then he throttled the motors to mere idling speed, pointing the plane’s nose groundward.

Somewhere below was a small airfield belonging to an airplane company that had gone bankrupt during the depression. Agent “X” had passed it many times in his car. It was a possible landing place.

But it was marked by no lights, and the criminals had used all the landing flares. “X” switched on the electric landing lights in the wing. Under their glow he caught a faint glimpse of the field he sought. The ghostly tops of the old hangars guided him.

Landing the huge tri-motor here would be a ticklish business even in daylight. At night, only a man of iron nerve and consummate skill could achieve it without cracking up. But the Agent side-slipped neatly into the small field, yawed the plane’s tail back and forth to kill speed. The air wheels touched the dim stretch of rusty green with hardly a bump, and he came to a stop in the center of the field.

Instantly he leaped out and examined the big plane. There were no Department of Commerce markings on it, no identification of any sort. It was a tramp craft of the air, an evil ship of darkness. Reaching under the control panel he opened up a petcock. The pungent smell of gasoline filled the air. It trickled into a dark puddle under the big fuselage.

Agent “X” waited till it spread. Then he got a cloth from under the pilot’s seat, soaked it with gas; balled it up, touched a match to it and tossed it into the plane’s interior.

Another match made a flaming cauldron out of the gas puddle beneath the plane’s fuselage. Agent “X” ducked and ran toward the dark outline of scrubby woods at the field’s farthest edge. He could hear a man’s voice calling out excitedly in a house near the field.

The landing of the tri-motor had aroused curiosity. People would be coming to investigate. But he would let them think he had burned up in the plane. This was an impression he was most anxious to give the criminals, also.

He looked behind him. Bright gasoline flames were licking up around the plane’s metal body now. Cloth and woodwork in the interior of the ship had caught, making the cabin window glow like evil red eyes in the side of some night monster. Then the partially filled gas tank exploded with the heat of the flames beneath. The instrument panel blew back into the cabin of the plane, and the cabin itself became a roaring furnace filled with sprayed gasoline. Windows blew out; white-hot flame melted the metal of the body.

As Agent “X” turned and plunged into the woods he knew there would be nothing left to show how he had escaped from the tail compartment that had held him prisoner.

Chapter V

A CAR chartered in a suburb near the old air field whirled Secret Agent “X” back to the city. Tense and impatient, he sat in the tonneau of the vehicle that rolled smoothly through the night, to all appearances a respectable, gray-haired business man.

“X” ordered the driver to stop at a certain street corner in the heart of the city. He paid his fare, strode briskly away in the darkness. Shadows of night enveloped him.

Four blocks from the spot where he had left the car Agent “X” suddenly entered the vestibule of a small walk-up apartment. Its halls, musty and dark, were lit by flickering gas light. Its janitress, a slovenly old woman, lived in the basement, appearing only when some tenant called her. Here was one of the many hideouts which Secret Agent “X” maintained.

In the seclusion of this small, cheaply furnished apartment, Agent “X” performed miracles with his hands. He stripped off the make-up which had made him resemble a middle-aged man. That disguise had served its purpose, was feasible no longer. The police would be on the lookout for the alleged bank examiner who went by the name of Garrison.

For the space of two minutes Secret Agent “X” appeared as he really was. The gray hair resolved itself into an ingeniously made toupee, which, when removed, revealed sleek brown hair beneath. The pastiness and wrinkles of flabby middle age left behind them the firm, unwrinkled flesh of a strong and distinguished face.

Even his few intimates had never seen Agent “X” like this; never glimpsed those features that were really his own. For they, like his name and identity, were secrets that he guarded with his life.

His face was remarkably youthful for a man who had been through so many strange experiences. It held power, character, understanding. The eyes had the clear brilliance of an original, penetrating mentality. There was kindness and humor, but unflinching determination in the even, mobile lips.

Hawklike strength marked the faintly curving line of the nose; scholarly intelligence was visible in the high, broad forehead. And, like the mystery surrounding his identity, there was mystery in those even features, too. For they seemed to change in different lights.

When the Agent turned his head, selecting a tube of make-up material, preparatory to creating another miracle of disguise, the oblique light brought out lines of maturity, revealed momentarily the visible records that a thousand strange adventures had written on this alertly youthful countenance.

His fingers moved, working the plastic, volatile make-up material over his face. Ingenious pigments covered the skin. This uncanny ability at disguise which made Secret Agent “X” a “Man of a Thousand Faces” had more than once formed the only barrier between himself and hideous death. Upon that ability he had over and over again gambled at desperate odds with life itself the stake. So far, he had always won. So far, no living soul had been able to unmask Secret Agent “X.”

When he rose from his mirrors ten minutes later he had become another person. His features now seemed thinner than formerly, his hair was sandy. The faint hawklike curve of his nose had been straightened. He appeared a mild looking young man of about thirty, with nothing to distinguish him from a thousand other such young men. He changed his suit, for a baggy pepper-and-salt tweed that matched the sandiness of his complexion, then walked quickly out of the apartment.

But he still wore the bullet-proof vest beneath this suit The strange assortment of things that he was accustomed to carry were hidden in the pockets. Inconspicuous though he looked, he was still Secret Agent “X”—a man of mystery and destiny.

At a mid-town garage, he ordered the fast roadster he kept there under the name of A.J. Martin, Associated Press reporter. His other car was still standing a few blocks from the Union Bank Safe Deposit Company. A telephoned call to another garage sent a mechanic after it. The Agent found it expeditious to keep several cars under various cognomens, as well as a number of hideouts.

In this other roadster he drove quickly to a street which held an assortment of small rooming houses. He entered one, asked for Thomas McCarthy, and was conducted to a rear room on the second floor. Here a man of about seventy, white-haired, but still alert and spry, came forward to greet him. He was a veteran police detective, retired now on his small savings and pension. The quick sparkle of his blue eyes showed that he still had an active interest in life.

“Hello, Mr. Martin,” he said. “What can I do for ye, my boy?”

Agent “X” smiled. McCarthy and a few others like him, were among the small number of trusted persons he occasionally employed to aid him in his daring work against the underworld of crime. They shadowed suspects under his direction, supplied bits of information valuable to the Agent. But they did not know that they were working for the greatest investigator alive.

“I’ve got a little job for you, Tom,” the Agent said. “Some fellows I’m watching made a get-away by plane from an airfield outside this city. I want you to hang around that field for about twenty-four hours and let me know what you see. There’s fifty bucks in the job. Would you be willing to tackle it?”

“Would I?” Thomas McCarthy beamed. “It ain’t the money, of course,” he qualified hastily. “It’s just that a feller don’t like to get rusty — and I like to do what I can to help you, Mr. Martin. You’re a hard working newspaper chap with a head on your shoulders. Some day they’ll make you editor of the whole damn sheet.”

“Maybe,” smiled Agent “X.” “And maybe I’ll get fired.”

He took out his wallet, drew out five ten dollar bills and handed them to McCarthy. The old headquarters dick tried to conceal his interest. But Agent “X” knew that the man needed new clothes, knew that this fifty dollars represented money to buy things for numerous small grandchildren. The old man’s pension was a barely liveable one.

“I don’t like to take anything till the job’s done,” said McCarthy, pocketing the bills. “But I’ll give you your money’s worth, boy. Lead me to that field.”

GIVING instructions as he drove, Agent “X” went back along the route that the gangsters had followed when they had taken him prisoner in their closed car. Though his eyes had been taped, he followed it accurately, coming at last to the field from which the big tri-motored ship had taken off.

This proved to be nothing more than a huge open lot where a real estate development had fallen through. But the marks of the ship’s air wheels in the turf showed plainly. A barnlike building at one end of the open field held sliding doors. There were other buildings around the field’s edge; old sheds, a neglected junk shop, a warehouse with windows boarded up.

“Keep out of sight,” whispered “X.” “Watch that big building over there. I’ll stop by at your place tomorrow.”

“O.K.,” said McCarthy. Then he drew Agent “X” back into the shadows for a moment spoke eagerly.

“I’ll put you wise to something since you’re a bright lad. I was talking to Captain McGrath over at the Tenth Precinct Station this afternoon. There’s gonna be a commissioners’ meeting in this city tomorrow night. Police chiefs are coming from all over the country, and a big gun named Beale is gonna give a talk. He’s a professor of criminology or something. Maybe if you could get into this meeting, young feller, you’d get a lot of hot copy for your sheet.”

Agent “X” grinned and nodded. “Thanks for the tip, Tom — but I happen to know about it already. There’s only one thing wrong — the press is barred. This commissioners’ conference is strictly secret. There’s been a lot of crime lately — and they’re going to see what can be done about it. Any newspaper man who tried to break in would get shot.”

McCarthy winked. “I’ll speak to McGrath, anyway. Maybe I can pull some strings and get you a side seat. You’d get a scoop on all the other sheets in town then.”

Agent “X” shook his head, patted McCarthy’s arm. “No use, Tom. It’s private, I tell you. Unless you’re a commissioner you don’t get in. Don’t go getting yourself in hot water on my account.”

McCarthy did not know that, because of the alarming spread of crime throughout the United States, the police heads of a score of cities had come together to work out some unified method of combating the criminals. He did not know either that Professor Norton Beale was classed as the cleverest, criminologist in America.

Agent “X” left McCarthy posted, returned to his parked car, and headed back into the city. As he drove he wondered about that important conclave scheduled for the following night. The public at large would never know what transpired behind those locked doors. The police were desperate. They would be instantly suspicious of any outsider seeking to gain admittance.

Secret Agent “X” knew that. But he also knew that he would find out what happened at that meeting — by a method all his own. He doubted that even the combined brains of a score of police heads and a great criminologist could trap the nationwide organization of criminals now operating. He’d had overwhelming proof of their originality and daring already tonight.

IT was just two hours after the raid on the Union Bank Safe Deposit Company when Agent “X” drove once again to within a few blocks of that institution, parked his car and walked forward. Several yards from the bank he stopped in the shadows. Police were still outside. Newspaper men still hung about. Inside all was confusion and activity as insurance investigators and special men from the bankers’ association went about their work.

Agent “X” made no attempt to re-enter the bank till nearly two thirty in the morning, when the building was again left alone except for two special watchmen outside and one within.

The city lay dark and still; and this time Agent “X” advanced slowly along the street on which the bank faced. When the patrolling bank guard came opposite, “X” swiftly drew his gas pistol and fired it in the man’s face.

The guard collapsed as the harmless gas instantly took effect. Agent “X” carried his inert body to a vestibule near by, propped it up. The guard would be out for at least half an hour — long enough for “X” to work. He waited at the corner till the other guard came around it, disposed of him in the same way.

Then he once more went to the bank’s doors. A special chain and heavy padlock now protected them. Agent “X” easily opened this with his tool kit. The slow steps of the third guard sounded inside. Agent “X” gave this man a dose of the anesthetizing gas.

Quickly then he continued the secret work that the criminals had interrupted, the daring and unconventional activities that he believed were necessary tonight, justified by the fact that he was on the track of something so vast and dangerous in scope that a whole nation lay helpless in its grasp.

All valuables had been taken from the big vault upstairs, but the safe deposit vault was intact. He went directly to the latter, opened the grille, and found a metal box marked 3071. Guarded by the bank and the full majesty of the law, this box nevertheless contained the property of a former underworld character, a gambler known as Bill “Diamond” Quade because of his fondness for headlight-size diamonds. A special tool with pivot extensions was necessary to open this box.

With eager fingers Agent “X” went through its contents. There was the deed to Quade’s house, his will, a packet of receipted bills. The Agent passed by these, came at last to several books of stock certificates. They had all been issued by the Paragon Cosmetics, Inc., a small wholesale firm, the shares of which were not even important enough to be listed on the exchange. Yet Quade had seen fit to buy many hundreds of these shares. Why?

That was what Agent “X” sought to find out. It was the tip-off that Quade was receiving a fabulously big income from a certain obscure stock that had brought “X” to the bank in the first place. Quade in a drunken moment had boasted to an underworld crony. A whisper of that boast had reached the Agent’s ears.

He pocketed one certificate, slipped the others back into the box and closed it. In a moment he was shutting the grilled doors of the safe deposit vault behind him.

HE drove swiftly to the vicinity of another hideout now — one that was far uptown. He had not had cause to visit it for weeks. But it contained the most complete equipment of all. He parked his car blocks away, walked along a wide drive that skirted the river, turned down a side street by a high wall.

Over the wall rose the roofs and gables of a stately house left vacant by the litigation of heirs. This was the old Montgomery Mansion.

For a moment his body seemed to blend with the shadows along the wall. Then he inserted a key in a hidden lock, passed through a low door. He entered a once beautiful garden, now fallen into ruin. He crossed this to a rear door of the old house, entered through the basement, and continued till he was close to the butler’s pantry. Now suddenly he swung a tier of shelves outward, slipped through the opening, and closed it after him. He was now in a small and windowless chamber, the existence of which no one searching the house would ever guess.

He clicked on an overhead light, disclosing shelves and cabinets of complex chemical and electrical paraphernalia. Here also was a small, dark room for developing photographic films and prints. Here were microscopes and equipment for studying fingerprints. Here were the things that made the Secret Agent master of a dozen sciences.

He brought out the one stock certificate he had taken from the bank’s vault, set to work immediately. His eyes shone with a bright, eager light as he studied that harmless looking oblong of paper. The company’s name was carefully engraved upon it, together with the date of issue, the dividend it was supposed to pay, and the corporation rulings.

With a small hand-glass Agent “X” went over every inch of both sides, but he raised his head unsatisfied. Next he took a bottle of colorless fluid end applied it deftly over the face of the stock issue. This liquid was mixed to bring out secret inks. But nothing showed.

The Agent applied heat now; patting the stock on a flat electric warming plate, careful not to burn it. Still no writing or marking was revealed.

He nodded to himself, turned to a square glass cabinet that reposed on a shelf. He took this down. It was air-tight, with a small motor and air pump attached. He placed the stock certificate inside the cabinet face upward, started the motor pump going, and exhausted the air within.

When a small dial showed that a vacuum existed inside, the Agent dropped some white crystals in an attached receptacle. Carefully he fitted a screw cap over the receptacle, lighted a small burner under it, then opened a tiny valve in the slender brass pipe that passed into the cabinet.

He was submitting the stock certificate to the most delicate test known to detect secret writing — the sublimated iodine test used by Captain Yardley and others of the American Secret Service during the World War.

A heavy, purplish vapor appeared inside the glass cabinet as the iodine crystals heated. The vapor descended sluggishly on the face of the stock certificate. It settled into the very pores of the paper; filling every minute depression in its fibers. And, when the vapor lay like a dark, unwholesome smoke barrage over the face of the stock certificate, Agent “X” opened the cabinet and took the document out.

Then breath hissed between his teeth. His eyes became like pin-points of polished steel. For, on the white surface of the stock issue, something had appeared. It was the lifelike, spine-chilling outline of a horrible creature — an octopus with tentacles extended and beak thrust forward. This was the secret marking that the other tests had failed to show up until the sublimated iodine vapor had forced its startling revelation.

Chapter VI

FOR seconds Agent “X” stared down at this ghastly symbol. There was no name, no number — only this hideously realistic outline of the octopus. It set the stock issue apart as though some devilish curse had been laid upon it. “X” guessed it had significance far deeper than appeared. The mark had been placed there by a masterly brain to guard against the possibility of forgery. It appeared as a sinister warning to any one bold enough to attempt an imitation of this paper.

Agent “X” put his vacuum cabinet away. In the fresher air of the room, the iodine vapor evaporated, and the strange mark was slowly vanishing. At the end of two minutes it had entirely gone. The stock appeared unmarked, innocent again. Agent “X” pocketed it.

It was now nearly four in the morning. The Agent had had no sleep. But, while working on a case, he seldom indulged in rest. Dynamic, indefatigable forces appeared to drive him on.

He left the hideout as he had come, walked swiftly to his parked roadster. Once more he headed the car toward the suburbs. He had another definite objective now. The discovery of the octopus seal on the stock had opened up a new line of investigation.

The whole city was cloaked with the chill darkness that precedes dawn. Somewhere far away the dull rumble of a truck sounded. Fitful wind stirred the branches of the trees as he came to the suburb. All else was still.

Bill “Diamond” Quade’s address was in the secret file of the Agent. He had taken pains to learn it when the mysterious tip-off had come. Quade, luxuriating in new-found prosperity, had bought a huge house in a fashionable suburb of the city. He had sold his gambling establishment, joined a country club, taken to bridge, golf and horseback riding. Many of his new friends were unaware of his shady past.

Agent “X” left his car a block away. He vaulted over the stone fence surrounding the Quade estate, strode quickly across a dark lawn toward a big house.

Somewhere a chain rattled. Agent “X” stopped. He listened for seconds, then gave a low, peculiar whistle. It was faint, musical, with a ventriloquistic quality. It was the whistle of Secret Agent “X”—unique in all the world.

In the darkness beyond a dog growled softly. Agent “X” repeated his strange whistle. It was not loud enough to carry inside the house. It was meant for the dog’s ears only. The animal’s growl changed to a low whine. Agent “X” approached quietly.

A huge police dog was chained in front of a kennel. “X” walked forward confidently, patted the dog’s head, spoke a few low-voiced sentences. His uncanny ability in making friends with animals had stood him in good stead often before.

“Quiet, old fellow,” he whispered. “Stay out of this.”

He strode on toward the house, leaving the dog gently thumping its tail on the ground.

There were double locks on the doors of the Quade mansion, tightly closed shutters on the windows of the ground floor. Quade’s contact with the underworld had made him suspicious, apparently. These locks gave Agent “X” trouble. He discovered, too, by probing with his small flash that the doors and windows on this first floor were protected by a delicate alarm system. The wires of it were deep inside the framework.

He shrugged, glanced about him. Huge trees towered over the big house on the west side. He glimpsed the dim outlines of a porch roof.

His rubber-soled shoes, of special pliant leather, were light, skid-proof. He crossed quickly to a big tree, studied its branches for a moment. Crouching low, muscles tautly balanced, he leaped suddenly straight upward, swift and dexterous as a cat, and caught the lower branch of the tree. In a moment he had pulled himself up.

HE climbed to another branch higher still, swung along hand over hand, dropped lightly to the top of the porch roof, landing on his toes.

This window was unshuttered; but a minute inspection showed that the same complex electric alarm system was wired here.

The Agent took out his tool kit, selected a small diamond-set glass cutter. Quickly but quietly he drew this around the glass just inside the sash. When the lines were complete he took a small rubber suction cap from his pocket, pressed it to the glass. It clung closely as a burr to clothing.

Delicately he pressed with his fingers against the glass. There came one faint, quick snap as the glass broke along the lines he had cut. It did not fall inwards, for his suction cap held it. He turned the glass edgewise, lifted it out and laid it down on the roof away from the window. In a moment he was inside the house.

There was a bed in the room he entered; but it was unoccupied. There were many vacant rooms in this big house which Quade’s egotistic love of display had made him buy.

Agent “X” tiptoed out into the hallway. A thick carpet deadened his footsteps here. He came to the top of a flight of stairs, moved softly down them. When he reached the bottom he clicked his flash on again for a moment, fingers held over the small lens so that only the thinnest ray of light came through.

With this to guide him he prowled about the lower floor of the house till he had located a room which gave evidences of being Quade’s den. There was a liquor cabinet here, smoking paraphernalia, a big roll-top desk. The Agent’s eyes gleamed brightly as they fell on this.

Before opening it, he crossed the hall outside and located the hidden, inside switch which disconnected the burglar alarm. He opened it, unlocked a side door. This would give him a quick exit in case an emergency arose.

Back in Quade’s den Secret Agent “X” went to work on the big desk. This was locked, too, but the Agent opened it easily.

He probed his light among the drawers and pigeonholes it contained. The first five minutes of search proved disappointing. The only documents were racing sheets and charts. Quade was evidently an addict of the ponies.

Then Agent “X” paused suddenly. He crouched and turned. To his alert ears had come distinctly the sound of cautious footsteps somewhere on the floor above. The carpet muffled them, but a board squeaked twice. Then he heard movement on the stairs.

“X” CROSSED the den on silent, catlike feet, moving behind one of the heavy brocaded silk draperies by the window. Here he waited while the footsteps roved about the hall. Suddenly a light clicked on in the hallway. Agent “X” reached into his pocket, took out a handkerchief, tied it over his face. There were two reasons for this action. He didn’t want his disguise of A.J. Martin revealed. And, if he were seen by anyone, the handkerchief over his face would give him the appearance of a common burglar or house thief.

Against the light in the hallway beyond the door of the den a bulky figure showed. The man was thick-necked, pink-faced; small, squinted eyes were sunk in rolls of flaccid flesh. He was wearing a blue tasseled dressing gown, thrown over wrinkled pajamas. Carpet slippers were on his feet. A huge, blue-steel automatic was clutched in his stubby fingers. Agent “X” recognized the face and figure of Bill “Diamond” Quade.

There was an ugly scowl on the ex-gambler’s face. The big gun was steady in his hand. He shuffled about the hall, started toward the side door which Agent “X” had unlocked.

Holding his lips in a peculiar position, Agent “X” made a noise in his throat — a dry, deliberate cough. But, because of his mouth position, the sound was ventriloquistic. It seemed to come from the other side of the den.

Instantly the sound of Quade’s shuffling footfalls ceased. For seconds there was complete silence. Then Quade approached the den stealthily. One pudgy hand stole around the door jamb, clicked the light switch, flooding the room with light. Once more Agent “X” made the coughing sound.

There were two sets of brocaded draperies in the room, one on each side of the big shuttered window. Both reached all the way to the floor.

The ex-gambler, Quade, eyes steely bright, pointed his gun at the one opposite “X.”

“Come out of there, rat,” Quads grated. “I hear you. I’ve got you covered.”

Agent “X” was silent, watching this obese product of the underworld through the semi-transparent fabric. He could see Quade’s face plainly, see the great bulbous features, the jowls almost like a dog’s, the glittering eyes. Quade was sure he had his quarry trapped, sure that the sound he had heard came from the drapery opposite “X.”

“Come out, I say, or—”

Still “X” was silent. Quade went forward resolutely, thrust the muzzle of his automatic against the drapery. His back was partially turned to Agent “X.”

At that instant, so quickly that Quade hadn’t even time to turn. Agent “X” stepped out of his hiding place and pressed the snout of his own gas gun against Quade’s pudgy neck. Under its cold muzzle the rolls of unhealthy flesh turned white.

“Drop that gun, Quade!” he said. “Go over to your desk and sit down. I want to talk to you.”

Chapter VII

QUADE’S whole flabby face had turned a pasty white. The gun dropped from his shaking fingers, thudded to the floor. Accustomed to using his wits to cheat his fellow man, Quade was no adept at physical violence. Now that his mysterious night visitor had the upper hand, the ex-gambler was cowed.

“Who are you?” he croaked. “For God’s sake don’t shoot. What do you want me to do?”

“Answer a few questions,” said “X” harshly. “Sit down.”

The former gambler slumped into the chair before his desk like a sack of meal falling over.

“Take that gun — out of my neck,” he said hoarsely. “I’ll talk — I swear I will.”

Here was the reason for all those locks, shutters and alarm systems that had impeded “X.” Quade was a coward. Soft living had shattered what little nerve he had left. Agent “X’s” eyes gleamed with grim humor. Quade’s craven spirit would make what he had to do easier.

“They say you’re a rich man, Quade,” rasped Agent “X.” “They say you’ve left your old haunts and your old friends and have put on a lot of swank.”

“I’ve got some money — not much — but I’ll pay you what you want if you won’t kill me,” said Quade wheezingly.

“You’ve got a nice tidy little income, I understand.”

“Investments,” said Quade. “I–I managed to save a little. I invested wisely. I’ve been lucky.”

“Splendid,” said Agent “X.” “That’s what I came for, Quade — to get a tip from you — about those investments. Maybe I’d like to invest, too. Just what investments do you recommend?”

Quade stiffened in his chair. His fat face was screwed up. He gripped the desk before him.

“I–I can’t say off-hand.”

“I haven’t found your name, Quade, listed in any broker’s office. The only stock you seem to have in your possession is Paragon Cosmetics — a small company few people have heard of.”

Agent “X” emphasized his words with another closer jab of the gun.

Quade almost screamed. “Yes — that’s it — Paragon Cosmetics. It’s a closed corporation — I’ve been most fortunate. They’ve paid me good dividends.”

“But you hold only a few hundred, Quade — don’t try to fool me.”

“My God — I’m not fooling you. They pay — nearly a thousand per cent. I’m not lying. They have made me rich.”

Agent “X” laughed harshly.

“I might think you were lying, Quade — if I didn’t know certain things. I was tipped off that you had a stock which was a bonanza. You talked, Quade, once when you were drunk. I want to get some of this remarkable stock, too. An issue that yields a dividend ten times more than the original price is worth having.”

Quade was silent for a second. He seemed to realize he had said too much. Agent “X’s” voice sounded softly in his ear:

“Better keep on talking, Quade, or—” Another jab with the gun made clear the meaning of “X’s” words. “Tell me more about this stock.”

“I can’t. I know nothing about the operations of the company. I bought it through a private broker.”

“His name?”

“It’s — it’s a woman. You’ve probably never heard of her.”

“Her name, Quade?”

“Tasha Merlo.”

Again Agent “X” laughed. There was no humor in the sound.

“So,” he said. “One of the underworld’s most brilliant women fences has become a stock broker, a promoter. Interesting, Quade!”

“You know her, then?”

“Only by reputation. Her specialty, I’ve heard, is disposing of stolen jewels. She is clever, beautiful. She mingles with society, finds customers in strange places. Am I right?”

“Yes — but she is no longer a fence.”

“I understand, Quade. She is a stock broker now. Give me her address.”

“It is useless,” said Quade. “It is a closed corporation, I tell you. All the stock has been divided.”

“Give me her address.”

Bill Quade shook his head. “Don’t ask me that! I — won’t.”

“You won’t?”

“No.”

Again Agent “X” laughed. Then he drew something from his pocket It was an apparently blank piece of paper — but one which the Agent had prepared. He laid it on the desk before Quade, handed Quade a pencil.

“Write as I dictate,” he said.

QUADE took the pencil, but shook his head again. “I’m not going to sign any sort of confession. I haven’t done anything.”

“This won’t be a confession,” said “X” mildly. His alert gaze was fixed on Quade’s face.

Suddenly the gambler drew in his breath with a hiss. He grew rigid in his chair. His eyes bulged. They were focused on the blank paper before him. On its surface the hideous outline of an octopus was appearing, written there by “X” in ink that turned dark under the influence of light. Quade’s reaction betrayed him. He had obviously seen this strange symbol before.

The Agent’s voice was low, insinuating. “You know the trademark, I see, Quade. Do you also know the man who uses it?”

Fear thickened Quade’s reply. “No — I swear it. I’ve seen the mark — yes. But the man — is a dark horse to me! He’s behind the stock — but I don’t know who he is.”

“Give me Tasha Merlo’s address then,” ordered Agent “X” again. “And if you lie to me about it — nothing, not even all your money, can save you.”

“I won’t lie,” babbled Quade. Something about this strange visitor’s manner and voice had struck terror to his soul. How had the man entered in spite of all the locks and alarms? How had he learned about the secret symbol of the Octopus? Quade gave the Agent the notorious fence’s address. When he had finished, Agent “X” took the gas gun from the fat gambler’s neck. As Quade turned in surprise, Agent “X” fired full into the man’s open mouth. The scream of terror that rose to Quade’s lips was blocked and stifled by the choking cloud of gas. It entered his mouth, nostrils, lungs, and, without a sound, he slipped sidewise in his chair and fell to the floor.

AGENT “X” stooped for a moment, pressed the point of a small hypo-syringe into Quade’s fat arm. In it was a harmless anesthetizing drug that would insure Quade’s unconsciousness for at least six hours. It would prevent Quade from warning the beautiful fence, Tasha Merlo, that a certain stranger had been making inquiries about her and the stock she now dealt in.

As quickly as he had come Agent “X” left the ex-gambler’s mansion. He had learned all he wanted from Quade. His next dealings would be with a clever, unusual woman, who was reputed to be as unscrupulous as she was beautiful.

In preparation for this visit Agent “X” made another trip to his main hideout in the Montgomery Mansion. Dawn would soon be stealing over the city, though it was still dark.

From a filing cabinet in his hide-out, Agent “X” drew the photograph of a man, with a recent newspaper clipping attached.

The man, with aristocratic features and a wispy blonde mustache, who stared out at him from the photo was an international jewel thief named St. John. The clipping told that he had made a daring escape from an English prison a week before. The photo was a copy of one held in the rogues’ gallery of New Scotland Yard. A British photographer in the pay of Agent “X” had shipped it to him along with others. It showed front and side views of St. John.

Agent “X” studied these for long moments; then set up his triple-sided mirror. The contours of the jewel thief’s face were not hard for a master of disguise such as “X” to duplicate.

At the end of five minutes, his long, skilled fingers had sculpted the plastic material into St. John’s features. Every line and plane was matched with amazing fidelity. St. John’s hair was blonde. Agent “X” selected a blonde wig from his collection that held hair of every texture and color. Over this blonde wig he mysteriously placed another that was jet black. It could be removed without disturbing the lower one. He did not duplicate St. John’s blonde mustache that showed in the photo.

When his disguise was complete Agent “X” went to a drawer which contained many articles of jewelry. Watches, rings, cuff links, scarf pins — all objects that he had occasion to use in his disguises. At the very bottom of the drawer was a gleaming woman’s necklace, apparently of blue-white diamonds. The jewels were really imitation, made of a special fused paste. Agent “X” slipped this into an inner pocket. Then, putting on a battered old hat and coat, he left his hideout for the second time that night.

The first gray streaks of dawn were breaking in the east as he walked to the address that Quade had given him — the address of Tasha Merlo. A few milkmen and push cart peddlers were the only living souls abroad. The semi-gloom of early morning seemed as sinister as the darkness. The evil forces of the night, soon to be put to rout, seemed gathering close over the city. Through shadowed streets more than one denizen of the underworld was stealing to his daytime hideout after a night of evil.

Agent “X,” hat pulled down, coat collar turned up, seemed like a criminal himself, hurrying to escape the probing light of day. He walked up to the house of Tasha Merlo, pressed the bell quickly.

It was minutes before any indication of life came. Then abruptly the door in front of “X” opened, and a giant mulatto stood in the gloom of the hall. His long face, almost Mongolian in its cast, had the fixed expression of a statue. His slanted eyes gleamed. He said nothing, waited for “X” to speak.

“I want to see Tasha Merlo,” the Agent said hoarsely.

“She is not up,” the mulatto answered. “You can’t see her. Who are you?”

“I must see her,” “X” said. “I have business.”

For an instant his fingers reached into his pocket. He drew out the top of the necklace, so that the faint light of the hallway caught its imitation jewels and sent prismatic flashes into the big mulatto’s face. The man’s eyes widened. “X” dropped the thing back into his coat.

“You understand why I must see Miss Merlo?”

The servant made a slight motion with his hand, beckoned “X” into the hallway. The door closed after him.

“Wait here,” the mulatto said. “I will see.”

HE disappeared like a dim wraith. It was ten minutes before he returned. He nodded then to “X” again, led him along the hall up a flight of stairs, into a room the door of which was hung with heavy black draperies. There was a strange scent in this room, exotic perfume that was heavy, cloying in its sweetness.

Two chairs, an ebony table, a divan, formed the only furniture. A shaded bulb overhead gave soft light. The place was almost like the rear room of some funeral parlor.

Again Agent “X” was left to wait. Several dark draperies hung along the walls. He could not tell from which Tasha Merlo would emerge. He had the feeling that eyes were watching him. His first intimation of her presence was the soft, strange drawl of her voice.

Agent “X” turned. A red-haired woman, beautifully molded in face and figure, had stepped from behind the draperies directly behind him. Her violet, heavily lidded eyes were upon him. The lines of her face showed little outward character. They were deceptively mild, almost babyish. Yet “X” knew that here was a woman whose record was on many police blotters. Here was a woman who had taken part in many crimes, before she had won her way to a position in the underworld as one of its most highly successful fences.

“You wish to see me?” the strange woman said.

Agent “X” studied her for an instant. She wore dark lounging pajamas, a silk robe thrown over them. Her hair was becomingly arranged. Her nails were sleekly polished. She did not look as though she had slept at all.

“Yes, I wanted to see you,” said “X,” again bringing a hoarse tremble in to his voice. “You may have heard of me. I am Horace St. John, of England.”

The woman eyed him, suspicion in her veiled glance.

“I have been told that Mr. St. John is a blonde,” she said, “like most Englishmen.”

Agent “X” nodded. He reached up suddenly, drew the dark wig from his head, leaving the blonde one exposed.

“You are right,” he said. “But — you may have read! I escaped from jail. I came across — a stowaway. I landed only last night. Naturally I didn’t want the police to suspect me if I were caught.”

“Naturally not,” echoed Tasha Merlo. She showed white teeth for the first time in a smile. She took a cigarette from a box on the table, lighted it with a small mother-of-pearl lighter. She blew smoke delicately through her shell-pink nostrils. “You are very clever, Mr. St. John — but why do you come to me? We have not, I think, had the pleasure of meeting.”

“No — but there was a man in prison who told me about you. You had helped him once, and—”

Agent “X” reached into his pocket again, drew out the glittering necklace. Even the most expert gaze could not have told that the diamonds were not genuine. A chemical test would be necessary to prove that. Tasha Merlo’s eyes rested on it speculatively.

“I thought perhaps,” said the Agent with assumed hesitancy, “that you could — er — dispose of this for me.”

Tasha Merlo laughed merrily. She shook her gleaming red head. Her eyes shone with a light that might have been amusement.

“I am no longer in the business which your friend no doubt told you about. I am sorry that I cannot help you.”

“You won’t pay me anything for this then?” the Agent asked. Deep disappointment seemed to be in his tone.

“No — I am sorry, my friend.”

The Agent took two steps nearer the woman, the diamond necklace dangling from his hand.

“It’s true then — you have gone into another line of work? I heard rumors of that; heard you’d become interested in stocks.”

This time Tasha Merlo threw back her head and her laughter was a silvery tinkle in the quiet of the room. The white curve of her throat was childlike. The Agent watched her narrowly, sensing a strange undercurrent behind her mild actions, an undercurrent as sinister as the unseen forces of evil menacing the nation. Her next words gave his suspicion startling proof.

“You amuse me — Mr. St. John. You are a good actor — but facts are against you. Three days ago I received a certain cablegram from England, asking for a loan. It was from an escaped jewel thief — the real St. John. I happen to know you are an imposter. And — if you will look behind you, not too quickly — you will see why it doesn’t pay to trick Tasha Merlo.”

With the woman’s soft laughter echoing in his ears, Agent “X” turned, slowly, as she had suggested. A faint prickle that seemed to start at his feet and work up along his whole body followed.

On the floor directly behind him two great dark shapes were visible. Predatory, triangular heads swung low, green eyes staring at him fixedly, two fierce leopards crouched there. They had entered the room and crept up so silently that he had not heard the whisper of their padded feet. Their taut bodies and snaky, quivering tails showed that they were ready to spring.

The woman’s voice sounded, low, mocking.

“At a word from me, Mr. — er — St. John, they will tear your throat out. The slightest move on your part means death!”

Chapter VIII

THE great cats’ merciless eyes backed up the woman’s statement. Ferocity and bloodlust gleamed in them. These beasts were eager to kill. Agent “X” had been close to death many times. He knew now the chill whisper of its wings beat about his head. He stood motionless.

“Satan and Nero,” the woman drawled. “They are my pets, my watchdogs. They have killed for me before. They will do so again. My will is their only law.”

Tasha Merlo laughed, betraying the subtle cruelty that lurked behind her innocently childish face. Her words revealed a hidden strain of sadism. Agent “X” sensed that she would enjoy seeing him torn by the cats. She clucked at them softly. They remained where they were, frozen statues of menace.

The woman sidled up to Agent “X,” faced him. Her violet eyes were alert; the pupils contracted to cold pinpoints of cunning. Her childish lips twisted mockingly. She tapped his chest with one flexed finger.

“Now,” she said, “you will tell me who you are and why you came here posing as St. John!”

The Agent stared back at her, his own eyes unfathomable. She repeated her question more harshly. He shook his head.

The woman stepped back, then struck her hands together. For an instant he thought it was the signal that would send the leopards leaping upon him with slashing fangs and claws. But instead the tall man servant entered the room. The mulatto’s nostrils dilated at sight of the animals. His huge body trembled.

Ignoring the servant’s evident terror, Tasha Merlo snapped an order, gesturing toward Agent “X.”

“Search him, Basson. Take everything from his pockets and bring what you find to me.” She turned her back, walked in lazy, languorous strides toward the couch, seated herself. The mulatto, Basson, keeping an eye on the crouching leopards approached “X.”

The Agent stiffened. He couldn’t afford another search of his clothing. He couldn’t afford to have his mysterious personal effects found again.

Disarmingly he reached up, unclipped the fountain pen from his vest pocket. Tasha Merlo, her violet eyes alert, hissed a warning. But she was too late. A slight pressure of the clasp on the pen under the Agent’s quick finger, and a thin jet of tear gas shot into the manservant’s face. Basson cried out, lurched away, rubbing his eyes.

Tasha Merlo had risen from the couch, her soft childish face convulsed in fury. She shouted one strange word. And the crouching leopards, like streaks of snarling, spitting lightning, launched themselves at Secret Agent “X.”

Only the springlike coordination of nerve and muscles saved the Agent from that first fierce leap. He hurled himself sidewise, dropped to one knee, ducked. The raking claws of one of the leopards passed so close that he could feel the swish of air on the taut skin of his neck.

The leopards checked, turned furiously to spring again. But Agent “X’s” hand flashed out He swept the end of his fountain pen in a flashing circle, spraying tear gas into the deadly, gleaming eyes. The beasts snarled and spit viciously, huge bodies convulsed, green eyes closed.

Then the full effects of the smarting chemical in the gas took effect.

One of the leopards opened his huge mouth in a coughing roar. He pawed at his eyes, tail lashing furiously. Agent “X” stood perfectly still. Basson, the mulatto servant, made the mistake of trying to slip from the room. His own eyes still blinded with gas, he stumbled against the small table, fell, fumbled to get up again.

Instantly one of the pain-crazed leopards detected the movement, sprang toward it with blind fury. Its ripping, terrible claws imbedded themselves in the servant’s shoulders. The man’s horrible scream split the air as he crumpled beneath the animal’s weight. The other leopard leaped to join its mate. Basson, helpless under the ravenous claws, screamed chokingly again.

Tasha Merlo gave an answering scream. Her face had gone dead white. “Satan! Nero!” she commanded shrilly. “Stop! Come here!”

BUT the leopards had tasted blood and the pain of the tear gas still in their eyes had driven them to savage frenzy. They ignored their mistress. Agent “X” fired his gun again straight at the animals’ huge heads. But this second spurt of gas sprayed futilely against the cats’ closed eyes. He flung the pistol at a sleek, tawny body. The leopard roared as the weapon struck, but he only clawed the servant more furiously.

Agent “X” whirled as Tasha Merlo drew a small revolver from her sleeve. In a bound, before she could aim at him, he had reached her side and snatched it from her fingers. While she screamed at him wildly, he walked up to the leopards and pressed the muzzle of the gun close. In quick succession he fired a shot into the head of each animal, behind the ears. The growls stilled abruptly in their hairy throats. They rolled over on the floor.

But the rug beneath them where the body of Basson lay was a stained and sodden shambles. The servant was dead, his throat torn horribly by the tawny beasts’ teeth and claws. Agent “X” felt sickened. He turned as the shrill voice of Tasha Merlo rose wildly.

“You have killed my pets,” she cried. “I will kill you — kill you for that!”

Contempt curled the Agent’s lips. He pointed toward the dead man on the floor. “What about him? He is dead. The cats killed him. You seem more worried about them than about the life of a man.”

“Any servant will do,” said Tasha Merlo angrily, “but Satan and Nero can never be matched. You—”

The Agent silenced her by suddenly turning the gun in her direction. His eyes were flaming with the intense, dynamic light that had power to cow those upon whom it blazed. He came close to the woman, looking at her steadily.

“I am not sorry I killed your pets, as you call them. And now you are going to talk. You will answer certain questions.”

The woman flinched; but she tossed her gleaming red hair back with a show of bravado. “I will answer nothing,” she said.

Agent “X” reached into his pocket, and abruptly drew out Quade’s stock certificate. He thrust it before Tasha Merlo, watched her intently, and saw her face muscles stiffen.

“Some of your own merchandise,” he said. “You recognize it, I see!”

Tasha Merlo compressed her lips grimly. For seconds their eyes clashed. Tasha Merlo looked away from the Agent’s piercing gaze. She seemed suddenly unsure of her ground.

“What is this stock?” he pressed. “I know you gave up the lucrative profession of selling stolen goods to peddle it.”

Her look grew more defiant. “Whatever I may or may not have done in the past, my present business is legitimate. Could you tempt me with that necklace? No. If you are a police spy, you have failed. There is nothing illegal about a woman’s acting in the capacity of broker for a corporation.”

Tasha Merlo was stalling. Agent “X” stepped closer.

“And I suppose there is nothing illegal about a stock issue that brings in a dividend of one thousand per cent,” he said softly.

The woman’s baby smooth face seemed to harden. “Who told you it paid that?”

“Never mind — that is beside the point!”

Tasha Merlo was silent. Abruptly “X” spoke again:

“It may interest you to know that I have learned something — this certificate bears the mark of the Octopus!”

AT this the woman’s face went chalk-white. She raised a hand to her breast. Her eyes roved over his face. She breathed quickly, and he edged toward her. Suddenly fear supplanted every other emotion in her expression. Her voice grew husky.

“Well — what of it?”

“You are going to tell me who he is,” said “X” harshly. “Certain facts I’ve already guessed. Others you are going to give me.”

“No! No! No!” the woman said wildly. “You’re trying to bluff me again — as you did with that necklace. You’re lying. You know nothing!”

“I suspect,” said “X” evenly, “that you are selling stock in one of the strangest corporations that ever existed. I suspect that you gave up your work as fence because you found it more profitable to act as the representative of a nation-wide organization of criminals. I am laying my cards on the table, you see.”

The woman nodded slowly, staring at him with new interest, a certain veiled awe in her violet eyes.

“I understand, now,” she said, almost in a whisper. “You must be the man they call Secret Agent ‘X.’ No one else could have guessed — so much.”

Agent “X” was silent. The woman spoke again, as though submitting to a will she felt powerless to combat.

“I will show you all the data I have,” she said. “It is not much. I am acting only under instructions. But come.”

Moving callously by the still forms on the floor, Tasha Merlo led Agent “X” through a curtain and into another room furnished only with a few chairs and a large old-fashioned desk over against one wall. The desk was tall, made of brown, richly polished wood. Tasha Merlo walked directly to it.

“Here,” she said, “is all I have.”

“X,” watching for possible treachery, half expected her to pull another gun or give some secret signal. But he did not anticipate the one thing she suddenly did. For Tasha Merlo abruptly ducked, plunging straight forward through what appeared to be the bottom of the desk. In one flashing instant she had disappeared from sight, and a metal door under the desk, painted to look like wood, had slammed shut. The Octopus’s beautiful, cunning representative had escaped.

Chapter IX

THE Agent stood still for an instant, chagrined that he had allowed this clever, guileful woman to outwit him so neatly. But on the whole he was satisfied. Her words, her desperate desire to escape, were proof that his suspicions were correct.

The Agent walked quickly to the desk, stooped and examined the false bottom, with the door beneath it. He struck the false wood with his knuckles. It was thick and firmly fastened now on the inside. Given time, he could get through into the mysterious passageway that must open behind it. But Tasha Merlo must already be far off. Agent “X” turned his attention to the top of the desk.

He went through the drawers; saw quickly that the woman had been too clever to leave anything incriminating there. A book listed many shares of Paragon Cosmetics. It gave dates of sale. There were references to the collection of dividends. But there was no list of customers.

The telephone on top of the desk rang sharply, interrupting the Secret Agent’s examination of the book. He took the receiver cautiously from its hook and pressed it to his ear.

“Long distance,” the operator intoned. “Boston calling.”

“Hello,” a man’s voice said impatiently. “I want to speak to Tasha Merlo.”

Agent “X” remembered the voice inflections of Basson, the servant who had been so horribly slain. With the consummate art of the born mimic Agent “X” disguised his own voice.

“This is Basson speaking, sir. Miss Merlo is not in at the moment.”

“Not in!”

“She stayed at a friend’s house last night. I am expecting her back any moment.”

There was an instant’s pause. Then the man at the other end of the wire said irritably, “Have her call Fenway 8482 as soon as she comes in.”

“I will, sir.”

Agent “X” hung up. He was tense with interest now. The phone call had been a lucky break. His own talent as a mimic had turned it to good advantage. The man had not given his name but the Boston number could be easily traced. It was the same as having his address.

But first he must learn what the man wanted of Tasha Merlo. “X” frowned. One thing he could not do successfully — disguise his voice as a woman’s. He could not call the man and impersonate Tasha. For a moment the Agent seemed lost in thought. Then he nodded. There was a way.

He strode quickly back through, the room where the torn body of Basson lay beside the two dead leopards, and found his way to the street door. He stepped out into the chill morning air. He strode quickly to his parked car. He slammed through the still deserted morning streets. The traffic signals had not yet gone on. He made sizzling time across town, then cut down, swinging into Twenty-third Street. He didn’t stop till he’d reached the middle of the block, then drew up before an apartment.

A milk wagon was rattling away. A lean cat prowled across the sidewalk. Agent “X” went to the opposite side of the street from the apartment and looked up. A window on the sixth story was up, fresh morning air streaming in. No light showed.

He puckered his lips suddenly, gave that strange whistle that was at once eerie and melodious. It whispered along the still street almost like the call of some wild bird. He waited a few minutes, repeated it.

IN a moment a head showed at the open window — the small oval face of a girl, framed in masses of clustering, sun-gold hair. Then it was withdrawn, and the Agent moved quickly across the street, entered the apartment and ascended to the sixth floor.

He rapped at a certain door, and was met by a girl whose blue eyes were brightly alert. There was an eager look on her face. But her expression was baffled as she stared at him. Her gaze roved over his features with no sign of recognition. She waited for him to speak.

There was a twinkle of grim amusement in the Secret Agent’s eyes. The girl before him, Betty Dale, reporter for the Herald, was one of the few persons in the world who knew the details of his strange career. She was self-supporting, independent, modern. Her father had been a police captain slain by underworld bullets. She hated crooks and crime as much as “X” did.

She trusted the Secret Agent, had aided him often — yet she was never sure it was he until he made some direct sign. For the perfection of his disguises always fooled her.

The Agent looked along the corridor. No one was in sight. He raised his hand quickly, made a motion with his finger — tracing an X in the air.

Betty Dale nodded, smiled. A flush came to her cheeks. The sparkle in her eyes showed the stirring of a deep, abiding emotion.

“You!” she said. “I heard your whistle — woke up. Then I wondered if I had dreamed it.”

As though this betrayed something she did not want revealed, she flushed again. Deep in her heart she loved this man of mystery whose own face she had never seen. He had been a friend of her father’s. She trusted him implicitly, felt his strange dynamic power. Beside him, all other men seemed somehow insignificant.

“I’m sorry to get you up so early, Betty; but — there is a way you can help me if you will.”

Her eyes brightened still more. She was pleased, happy whenever she could aid Agent “X.” Even if it meant danger for herself.

“I’m glad you got me up,” she said. “We can have breakfast together — and a visit before I go to the office. What is it you want me to do?”

“Make a telephone call for me.”

The girl laughed merrily. “I hoped you had some real work for me — something big that I could help you do.”

“It’s not going to be as easy as you think, Betty. You’ve got to change your voice — and appear to be some one else.”

He explained to her then that he wanted her to mimic Tasha Merlo and call the man in Boston.

“You’ll have to be discreet, Betty. I must find out what connection this man has with Tasha Merlo. We must hurry.”

He coached her for nearly ten minutes, both in what to say and how to say it. He had Betty alter her voice to several different pitches before he found the one that resembled Tasha Merlo’s. When Betty had mastered the art of sustaining it she walked toward the phone; but he restrained her.

“Not here, Betty, I wouldn’t have that. You must make the call far from this apartment.”

Something in his voice brought her up sharply, took away some of the bright color from her face.

“You mean — there is danger?”

“There might be, for you, if this call was traced.”

“Who is this man in Boston?”

“I don’t know, Betty — but I suspect he is one of a group of criminals now operating in many States. The same group that is the direct cause of the commissioners’ meeting tonight. Perhaps you’ve heard of it. They are seeking ways to suppress a mounting crime wave.”

BETTY looked searchingly at Agent “X” with worried eyes. Because of her hidden emotion for him she carried a secret dread in her heart.

“I’m not afraid if you aren’t,” she said. “I know about the commissioners’ meeting. I wanted to cover it for my paper. But even the press is barred. I won’t be able to tell you anything about it.”

“You won’t need to, Betty. I intend to be there.”

The Agent spoke calmly. Betty shot him a quick, frightened look. She did not doubt that he would accomplish the seemingly impossible and attend the commissioners’ conference, though how he would do it she had no idea. But she knew that he would be in danger.

She had met the Agent in a becoming lounging robe slipped over her pajamas. Now she retired to her room and dressed quickly, while the Secret Agent waited.

When Betty was ready he hurried her out to his waiting car. She drew in deep lungfuls of the fresh morning air, smiled into his face. “X” felt the contrast of her bright, fresh beauty to the evil forces he knew were in progress even at this moment.

They stopped at a drug store many blocks away.

“Now,” he said, “do your stuff, Betty.”

He waited at her elbow as she called the Boston number. He held a palmful of coins ready, and she deposited them in the box when the operator said, “Ready.”

The conversation was brief. When Betty hung up and turned toward him the Agent smiled his approval. “Good work,” he said. “What was it, Betty?”

“I don’t understand,” she said. “He merely asked me how the ‘paper’ was selling and I said well. He said he was sending me some more today.”

Agent “X” nodded. He was satisfied with the results of the telephone call. He knew that the “paper” the man in Boston was talking about was more issues of the sinister stock. Like slowly moving tentacles the man who went by that name was spreading his influence over the country. Tasha Merlo was probably one of many stock salesmen. Through dividends paid on crimes already committed he was reimbursing his stockholders, and was raising money to finance new crimes.

“X” touched Betty Dale’s arm lightly. “I’m sorry, Betty. I don’t think I even have time for breakfast — but perhaps we can have dinner tonight, if you will.”

“Of course — but what are you going to do now? Can’t I help you some other way?”

“No, Betty — I’ve got to take a little trip.”

“Where?” The question was on her lips before she could check it. She never tried to probe into the Agent’s mysterious comings and goings. But he smiled now, squeezed her hand quickly.

“Boston, if you must know,” he said quietly.

Chapter X

THERE was no humor in the Secret Agent’s eyes as he left Betty Dale. He changed his disguise again to that of A.J. Martin, headed his car toward the suburbs once more. His gaze was grimly, bleakly intent. There would be no rest for him now. Once he had committed himself to a life-and-death battle against criminals, Secret Agent “X” was as relentless as Fate itself.

The trail he was to follow lay straight before him. He had visited Quade and Tasha Merlo. Now he must learn the name and activities of this man in Boston.

He sent his roadster whizzing along smooth concrete roads. He passed suburban houses, their inmates still asleep; passed green fields, sweet with the scent of morning dew on grass. He turned down a long avenue, rolled up to a high wire gate.

Behind this, an open field showed with airplane hangars looming at its side. Agent “X” parked his car, strode quickly through the gate. A mechanic strolled out of a hangar door to meet him, nodded sleepily.

“Howdy, Mr. Martin. Off on an early start this morning!”

“Yes.”

“Another hot story broke some place, I guess?”

Agent “X” grunted noncommittally. Around this field he was known as A.J. Martin of the Associated Press. His mysterious comings and goings were put down to his newspaper work.

“Get my bus wheeled out there, Joe,” he said. “The open one.”

His quick, precise orders snapped the sleepy-eyed mechanic into action. The man walked along a row of hangars, unlocked a door and slid it back. He vanished into the dimness of the building. Presently the orange and blue nose of a plane appeared as the mechanic trundled it out, a dolly under the tail. This was one of the two ships that Agent “X” kept on this field. He called it the Blue Comet.

It was a small, single-seater biplane with staggered wings, low camber and plenty of sweep-back. It might have been an army pursuit job except for its bright coloring. There was a compact cowling of the latest design on the radial motor. Speed, power, beauty were in the plane’s lines. Graceful as a hawk, swift as an arrow, the Secret Agent had selected and purchased it after exhaustive tests of many others. He knew what it could do, knew it as a horseman might know all the habits and capabilities of a fine mount.

Each brace, strut and wire had drumlike tautness. The doped surface of the stout wings gleamed. The engine was always gassed, oiled, and tuned to the highest pitch of performance.

Agent “X” slipped into a soft suede jacket, adjusted goggles and helmet. The mechanic wound up the inertia starter. Its mounting whine sounded as the Agent climbed into the plane’s single cockpit with its heavy crash pad and military lines. A moment and he switched on the ignition. The motor broke instantly into a smooth-voiced rumble. The small, stout plane seemed crouching like a bird anxious to leap into the sky.

The Agent warmed the idling engine for a few minutes in the routine manner of an experienced airman, then raised his hand for the mechanic to draw the chocks.

The radial broke into a roar that awoke murmurs along the tops of the hangars and sent blasting echoes across the field. The plane leaped down the macadamized surface, gathering momentum each second.

The take-off was a thing of swift, effortless beauty. The plane’s blue wings slanted up toward the sky. Its engine, snarling now in throaty, gusty power, pulled it into the air. The ship hurtled upward toward the feathery, early morning clouds with the speed of the wind.

Forty minutes passed. He came down out of the morning sky, landed on Boston Airport, gave his plane into the hands of a mechanic who also knew him as Martin. Immediately he went to a Boston garage where he kept a car.

The tracing down of the telephone number was a relatively simple job. In so far as its mechanical details went, he could have trusted it to a subordinate in the crime-combating organization he was beginning to build up. But he dared not risk a slip-up in this, the most promising clue he had yet come upon.

A half hour later he had traced the number down, driven to the address behind it. It was the residence of a prominent attorney named P. T. Van Camp. The Agent called up a newspaper office; spoke to a reporter who knew him as Martin, and got the low-down on Van Camp.

“One of the cleverest criminal lawyers in the country,” was the report.

Van Camp then was a mouthpiece, a man who used his brains and his education to save criminals from jail and the chair.

The Agent drove quickly to another part of the city; visited a small boarding house. Here he called upon a middle-aged private detective. The man was one of two partners whose business had gone on the rocks in the depression. His name was Sloan. He was fat, slow-moving, but ploddingly patient and reliable. He could be trusted to carry out orders to the letter.

Agent “X” transported him back to within a block of Van Camp’s house and there posted him. Sloan, like McCarthy, was ignorant of the identity of his employer. He thought “X” merely a smart young reporter on the trail of some special scoop story.

“Shadow Van Camp today,” the Agent said. “Stick to him like a burr, but don’t let him get wise. Find out all you can about him — and be careful. I’ll give you a buzz some time this evening.”

Agent “X” had another important task ahead of him. The commissioners’ conference was scheduled to take place tonight in his home city. He had intimated to Betty Dale that he was going to attend that conference. Impossible as this seemed, he had every intention of doing it.

From the same reporter who had given him the low-down on Van Camp, Agent “X” got the names of the various commissioners from New England cities who planned to attend the conference. One from an obscure city near Boston interested him. This was Commissioner Baldwin of West Foxbury. All of them, including Baldwin, must have received official invitations. Otherwise they would not be permitted to attend.

AROUND noon that day, Police Commissioner Baldwin of West Foxbury received an unexpected visitor. A tall, somber-looking man with piercing eyes and shaggy brows was ushered into his office.

There was an air of mystery and ponderous gravity about the stranger. He took a seat before the commissioner’s desk, eyed Baldwin steadily, not speaking until the secretary who had showed him in had left. Then he leaned forward in his chair and presented an engraved card to the commissioner. Baldwin took it wonderingly.

The card said: “L. Landors Sinclair, Special Representative of the Governor.”

Baldwin looked up quickly to meet the stranger’s steady gaze. Baldwin was tall, dignified himself; but somehow Sinclair seemed to tower over him.

“What can I do for you?” the commissioner said. There was a slight edge of uneasiness in his tone. The light in the stranger’s eyes and his manner seemed faintly accusing.

Sinclair cleared his throat importantly. “Don’t be alarmed,” he said. “There is no direct implication in my visit to you. You must view this purely in the light of an investigation.”

Commissioner Baldwin tensed. “An investigation, Mr. Sinclair? I don’t quite understand.”

Sinclair leaned forward, tapped the desk impressively. “Unknown to those most concerned, commissioner, the governor of this State is making a private check-up on police graft in this and other cities. Certain rumors have brought me to West Foxbury.”

The commissioner started visibly. The ruddiness of his face paled a trifle. “There must be some mistake,” he said. “My term in office, Sinclair, has been a spotless one. I challenge—”

Sinclair held up a formidable hand. “Your subordinates must be considered, commissioner. I’m making no charges. I’m investigating. But remember that the chief executive of this State holds you responsible for the inspectors, captains and lieutenants under you. The board of trade of this city has made a request that I—”

Commissioner Baldwin’s face turned white. “Good God! It can’t be! I—”

“If you don’t mind I suggest that you come with me, commissioner, and hear what the members of the board have to say. I want to record their assertions and your answers. Then I will have something to show his excellency, the governor.”

COMMISSIONER BALDWIN, now thoroughly on the defensive, picked up his hat and left word with his secretary that he did not know just when he would be back.

“This is most unfortunate, Mr. Sinclair, coming today,” he said. “I plan to leave this afternoon for the commissioners’ conference. I have an invitation in my pocket.”

“We’ll try to get the investigation over with as quickly as possible,” said Sinclair gravely.

It surprised Commissioner Baldwin to see that Sinclair drove his own roadster. The governor’s representative maneuvered expertly through West Foxbury’s main street, drew up before the one modern hotel.

“This isn’t the Board of Trade Building,” said Baldwin in puzzlement.

“For the purposes of privacy, the gentlemen have agreed to meet in my room, commissioner. You’ll appreciate that, I think.”

“Good lord, yes; if a whisper of this gets to the papers I’ll be ruined politically. Thanks for keeping it under cover. I can’t imagine what the Board of Trade is thinking of.”

Commissioner Baldwin was even more puzzled a moment later. An elevator whisked them up to Sinclair’s room. Sinclair opened the door for him, ushered him in. But no one was there, and there seemed to be no preparation for any sort of meeting. The commissioner looked around uneasily.

“I don’t understand. When are the others coming? You said—”

The commissioner’s tongue seemed suddenly clamped to the roof of his mouth, for the man who called himself the governor’s representative had drawn a gun. A look of fear and frenzy appeared on Baldwin’s face. He sensed suddenly that he had fallen into some sort of trap. This man wasn’t the governor’s representative. There was no investigation.

He stepped back, trying to jerk free the police special that he carried in a side holster, the only reminder of the days when he himself had been a cop.

But before he could even lay a finger on the butt of the gun the other man had fired. A cloud of vapor went full into Baldwin’s face, throttling the cry that rose to his lips.

Quietly, painlessly as a man going to sleep under an anaesthetic, his muscles went limp and he collapsed to tbe floor.

Sinclair pocketed his gas gun, crossed to the door, locked it. He came close and soberly contemplated the man at his feet. There was a shadow in his eyes. He regretted that he had been forced to trick and humiliate the commissioner like this. Baldwin seemed an honest, straightforward official. But daring and unconventional acts on occasion had always been a part of the Secret Agent’s technique.

The tall, gray-haired “Sinclair” whose make-up was just another of “X’s” ingenious disguises, believed that what he’d done was justified if it would in any way aid him to run down the vicious, nation-wide organization of criminals now preying on society. Baldwin would lie unconscious but unhurt here — and Secret Agent “X” would attend the commissioners’ conference in his stead.

Chapter XI

ARMED and vigilant cops stood outside the commissioners’ room that night. Each member of the conference was asked upon arrival to give proper identification, also to show the signed letter of invitation responsible for his being there. This letter was submitted to close inspection by an expert on counterfeiting and forging.

The police heads of a score of cities were getting a taste of their own medicine. They were learning how careful the law could be in excluding undesirables.

A police cordon efficiently ringed the building. Reporters were not even allowed inside. Behind the smiles and good humor of each commissioner there was realization of the serious import of this conference. Somehow they must arrange for a new and concerted drive against crime.

Agent “X,” disguised as Commissioner Baldwin, presented Baldwin’s credentials and invitation. He got in without trouble. Arriving early, he took a seat near the platform. Many other commissioners who knew Baldwin shook hands with him. But Agent “X” was guarded in his speech, careful to say nothing that might betray him.

Commissioner Foster, an old enemy of the Agent’s, was the master of ceremonies. It was he, with Professor Beale’s aid, who had arranged the conference.

Foster, tall, distinguished, with graying hair, and a black, close-clipped mustache, was dressed in full evening clothes. He spoke sonorously when the body of police heads was finally assembled.

“Gentlemen, we have come here tonight in response to a national emergency. We have come to discuss crime and crime prevention. We have come to review what has been done and to work out new methods of combating criminals along all fronts. As you know, gentlemen, major crimes throughout the United States have shown an appalling increase during past weeks. It seems almost that the lifting of the great depression has given our criminal elements new impetus.

“Whatever the cause, we are able to observe the effects. Bank robberies, kidnapings, extortions, murders, have all increased. This chart, gentlemen, behind me, will show you the statistics in graphic form.”

Commissioner Foster stood aside to let them see the huge chart on the wall in back of him, marked off in squares. Red and blue lines zigzagged across it. The red line at the top showed an ever mounting curve. A network of smaller red lines followed it.

“The small lines indicate the various types of major crimes,” said Foster. “The large line is crime in the aggregate. Both lines rise as you can see. And because of this emergency I have arranged to have our conference addressed tonight by a man outstanding in the field of practical criminology. Allow me to introduce Professor Norton Beale.”

The man who had been sitting in a chair on the platform while the commissioner made his introductory speech now arose. He was short, thick-set, with thin legs and immensely broad shoulders. He had the huge, leonine head and forceful air of a scholar.

There was applause as he stepped forward. Most of those present had read his books. All knew him by reputation. They were eager to hear his opinions on the alarming increase in criminal activities, hoping that he could suggest new and efficient methods of law enforcement.

But Agent “X,” watching and listening intently, doubted if even Professor Beale and this distinguished body of police officials knew quite what they were up against. Had whispers reached them that criminals had actually incorporated themselves and were selling stock to finance their vicious schemes? “X” was anxious to find out. He wanted to learn how much the police knew; see what methods of attack they had devised.

But Professor Beale’s speech was disappointing to “X.” Commissioner Foster hadn’t mentioned the possibility of the underworld organizing. Neither did Beale. He submitted his own statistics, showing the increase in crime. He traced sociological trends. He enumerated economic influence which made some of the commissioners yawn. Obviously, no one had seen the dread mark of the Octopus. Heavy-hearted, “X” watched as Beale directed two cops to bring out the latest police equipment.

Riot guns, gas guns, small and large caliber machine guns, were among the paraphernalia. Glittering, complex optical instruments of the latest design. A bullet microscope which could give conclusive proof as to what pistol a piece of lead had been fired from. The Greenough microscope for the scientific detection of dust. A micro-camera to give comparison of forgeries. A pressure microscope which could reveal numbers that had been filed off metal.

Professor Beale explained them all in precise tones.

“Criminals, my friends,” he said importantly, “grow more clever with every passing year. They employ science to outwit the law. We must employ science in turn to outwit them. The present crime wave is a challenge to the police forces of the entire country. We must press into service all available resources, moral, psychological, physical.”

BEALE walked to the back of the platform and drew forward a bulky apparatus on wheels which had been standing against the wall.

“Here, for instance,” he said, “is one of the most recent scientific aids in the field of practical detection. Two of my students helped me build it. Plans submitted to a number of European police departments have been approved. It will shortly be adopted in this country. I call it a fingerprint projector.”

Members of the conference tensed and leaned forward.

“There is a ground-glass screen here,” said Beale, tapping the top of the strange-looking box. “It’s surface is admirably suited to receiving fingerprints. The oily marks on the glass interfere with the refraction of light rays inside the box. They are picked up and magnified by a powerful lens in the projector and can then be thrown outward. Let me demonstrate.”

Beale walked forward, took down the statistical chart. Behind it on the wall at the rear of the platform was a four-foot square of silverized material. The professor switched out the main lights, focused the lens of his projector on this screen. Laying his hands on the surface of the glass, he displayed his own magnified fingerprints clearly outlined. The swirling convolutions glowed sharply for a moment in the darkness. Then he switched on the main lights again, and took a small leatherette case from his pocket.

“This instrument not only projects one set of prints,” he continued. “It shows two full sets — giving a chance for comparative study. It may surprise you all to know that I have here on file the prints of every man in this room. Commissioner Foster kindly helped me collect them for my demonstration. Glass slides have been prepared of them all. And—” Beale once again tapped his large box—“here at the side of the projector is a holder and another magnifying lens so that the prints on the slides and the fresh ones on the ground glass can be shown simultaneously on the screen. You follow, gentlemen, I believe?”

Agent “X” was irritated at this detailed rigmarole which, in the long run, would be only of superficial aid in the running down of criminals. He had come to this meeting with eager interest, hoping to find that the police were ready with some plan to check the terrifying wave of crime mounting daily. But it was plain that these men, who represented the keenest brains, on the forces of the law, were ignorant of the real gravity of the situation. Absorbed in his own thoughts, he hardly heard the Professor’s words. But Beale’s next announcement startled him to alert attention.

“As a concrete and visible proof of the practicability of this instrument I’m going to ask each of you gentlemen to step up on the platform in turn and have your fingerprints tested. Let us pretend, for the sake of argument, that there is an imposter in this gathering.

“Let us say he is the exact image of one of the commissioners invited, and that he stole that commissioner’s pass and credentials, even murdered the man he is impersonating. Such things have happened, gentlemen, in the history of crime. But fingerprints cannot be successfully imitated or duplicated. If such a man were here he would be quickly exposed.”

CHUCKLES went up from several quarters of the room. Professor Beale’s dramatic display of scientific detection was evidently taken lightly. But Secret Agent “X” had grown tense. Here was an unforeseen happening that had suddenly placed him in a dangerous spot — a spot where exposure and the end of all his plans might ensue. He had gained nothing by coming here. The police knew less than he did about the new menace that had arisen. But, because Beale had a scientist’s passion for visual demonstration, Agent “X” was up against it.

He hoped that some of the commissioners would laughingly dismiss the Professor’s suggestion. But, impressed by his eminence, or anxious to see how their prints looked on the screen they, one by one, moved toward the platform. Agent “X” suddenly realized that he was making himself conspicuous by not going up. All the others around him had. Their prints on file and those projected tallied.

There were only two men left now. They moved up onto the platform. The infallible machine proved them to be the persons they claimed.

“Only one slide left, gentlemen,” said Professor Beale. “This bears the prints of Commissioner Baldwin of West Foxbury. Will the commissioner kindly step up?”

Heads turned to stare at Agent “X.” He made no move to rise. The sharp eyes of Professor Beale focused upon him.

“Well?”

Agent “X” made no answer. The drawling, sarcastic voice of Beale sounded.

“One would think, if your identity here were not well known, that you had something to conceal, commissioner!”

A general laugh went up at what appeared to be a joke. But the eyes of Agent “X” held grim lights in them. This was no joke to him. It was a situation fraught with deadly possibilities. Of all the men in this room, he alone had seen the mark of the Octopus. Nothing must happen to impede his progress. And yet he seemed inescapably trapped.

His brain raced desperately. This was one of the most ominous situations he had ever faced. Suspicion was growing heavy in the air of the room, blotting out the friendliness. And for Secret Agent “X” to be unmasked now would not only mean the end of his campaign against the Octopus — it might mean the bitter end of his whole career.

Chapter XII

TENSELY alert, he shrugged when the titters quieted, spoke with magnificent calmness. “You’ve demonstrated the cleverness of your machine, professor. You’ve proved that it is highly efficient. Let us now go on to something else. Fingerprinting is only one phase of criminological work.”

A slight tenseness passed over the gathering. Beale laughed again.

“Really, commissioner, I wouldn’t make an issue of it, if I were you! Some of these gentlemen might suspect—”

He stopped speaking, and another general laugh sounded. Two commissioners, acquaintances of Baldwin, who had spoken to “X” when he first came in, leaned forward. One talked quickly behind his hand.

“Better go up, Baldwin! There might be some nasty gossip if you didn’t. Nothing to it, you know — just stick your fingers on that glass.”

Agent “X” nodded but he thrust his chin out stubbornly.

“I never did like to be railroaded,” he said. “Let him kid me if he wants to. I can take it. Some of these new-fangled notions get under my skin.” He added more loudly, “When you start fingerprinting the police it puts them in the same class with the crooks.”

Professor Beale laughed. “Nothing like that, commissioner. You misinterpret the purpose of this test. You’re making a mountain out of a molehill, if you’ll pardon my saying so.”

Commissioner Foster added his word. “You’re reputed to be a wide-awake man, Baldwin. In respect to our speaker this evening I think you owe it to us all to fall in line. You’ve got us on edge now to see what your prints look like.”

For a second the Agent’s eyes swivelled around the room. There were armed cops at all exits. The projector on the platform would instantly give proof of the fact that he was an imposter. Once the fingerprints had been compared he could not bluff his way out. He would be held, questioned, jailed. He could not expect any one to come to his defense.

“I refuse, gentlemen,” he said. “Just put it down to a stubborn temperament. If you think I’m a crook, get out a warrant for my arrest.”

The meeting grew tense. No one was laughing now. Professor Beale spoke with sudden biting vehemence.

“I said in the beginning that criminals have been known to impersonate men in high positions. So that no suspicion will fall on your head, Commissioner Baldwin, I suggest that you come up here at once and get this matter over with so that we can proceed with the conference.”

Agent “X” leaped to his feet to begin an angry retort. This seemed the best way of stalling for time. But he paused and turned his head instead.

From outside the headquarters building which housed the auditorium they were in, a sudden racket had come. A dull, jarring explosion, that shook the windows and made the floor under their feet vibrate. There was a second of silence. Then the noise of distant shouting; and a spiteful crackling. Agent “X” was the first to recognize that second sound.

“Gun fire!” he said suddenly.

The eyes of Professor Beale were upon him. Beale’s voice snapped out as Agent “X” turned toward the door.

“Don’t make your actions more suspicious than they already are, commissioner. If there’s a disturbance outside, patrolmen and detectives are amply able to take care of it. We are here to attend a commissioners’ conference — and I might add that you haven’t shown us your fingerprints yet. Your attitude is making it rather trying for us all — putting Commissioner Foster and myself in a difficult position.”

“Why not drop the whole business, then?” said “X” sharply.

“Because, commissioner, I am frank to admit that I think you have some reason for not wanting to match your prints with those I have here on file. It sounds incredible — but I have made a study of human psychology — and your actions—”

The shrill, unmistakable blast of a police whistle cut across Beale’s words. Another series of sputtering explosions came. These were unquestionably shots.

Half the members of the conference had risen excitedly to their feet. Commissioner Foster was looking anxiously toward the door. The Agent’s eyes clashed for a moment with Professor Beale’s. The shrewd criminologist undoubtedly suspected him of being an imposter. But “X” had bluffed it out so far. He made a last, vehement gesture.

“While we stand quibbling here, professor, criminals are active under our very noses. I suggest that we stop our child’s play and do some practical work.”

BEALE made an impatient, irritated exclamation. But Agent “X’s” words, backed up by the noise outside, started a movement toward the door. Commissioner Foster strode excitedly through the assemblage, into the corridor. A dozen other commissioners from various cities crowded after him. An inspector of a detective division came running up the stairs, shouting excitedly.

“There’s a robbery being pulled off right on this block, commissioner. Those diamond brokers on the corner — there’s a bunch of bandits in an armored car parked outside. They’ve cracked the safe. They’ve got a Tommy-gun.”

His excited flow of words was punctuated by the vicious rat-tat-tat of a machine gun. The conference disbanded in an uproar. Commissioners and subordinates alike ran to the front entrance of the headquarters building. One of them gave a hoarse cry.

A cop, his blue uniform sodden with crimson came reeling across the sidewalk and collapsed at the commissioners’ feet. Down the block, Agent “X” saw a long, low armored car. From a slit in its side a winking pin-point of flame showed intermittently. A dozen cops had taken refuge in doorways and vestibules along the street, service revolvers snapping. As “X” watched, one cop threw up his hands and pitched sidewise into the street The bandits were ruthlessly slaughtering the police.

Curses, excited orders, took the place of Professor Beale’s calm, scientific tones. Commissioner Foster, white-faced, bawled orders to an inspector. The inspector marshaled a squad-of plain-clothes men with an arsenal of riot and machine guns. They poured into the street; were met by a withering blast of bullets from the car at the end of the block.

This was warfare — warfare between the dread, organized forces of the underworld and the valiant defenders of the law.

A cop with a riot gun cursed, groaned, fell to the pavement, his weapon clattering from his hands. One leg had been shattered under him. He tried to hunch forward to pick up his gun again, leaving a smear of crimson behind him. Another blast of bullets ricocheted against the curb beside him, ripped into his body with the sickening spat of flattened lead. He jerked for a moment as though in the contortions of some weird dance, lay still.

AGENT “X,” white with fury at the ruthlessness of this killing, heedless of his own danger, darted across the pavement and picked up the slain cop’s weapon. The other police had taken refuge in doorways.

Not often did the Agent use a lethal weapon. When he did he could shoot with expert marksmanship. He crouched, braced the curved butt of the rapid-firer against his shoulder, pressed the steel trigger, slammed bullets down the block at that sinister black car. A masked figure came running out of the diamond brokerage office; leaped into the car before “X” could swing the cumbersome muzzle of the gun. His bullets played a tattoo over the side of the car. But its armor plate prevented them from doing any damage.

The flame that was the bandit’s machine gun showed again. Leaden death hissed in the night air around “X.” He flung himself flat on the pavement, gun snuggled in the crook of his elbow, steady eyes trained along the barrel. He aimed as close to the other flame as he could; pumped more bullets into the darkness.

The firing stopped. The big car leaped away with whining gears. Cops came out from under cover and the wailing, hysterical note of police sirens began to shrill along the street The car with the bandits in it spurted away.

The street was a bedlam of excitement now. The fierce shouts went up. In the second story windows of the diamond brokerage office a glow showed. Smoke began to plume out. A flame appeared like a greedy red tongue. Agent “X” started to drop the machine gun he had snatched up, then hastily cleaned off the finger prints he had made. He put the gun down, ran forward with a crowd of police and commissioners.

The fire in the brokerage office was gaining headway, showing that the raiders had left some highly inflammable material there, adding arson to safe-blowing. The blood-red glow of the fire spread along the street, adding to the horror.

At least six cops lay dead on the pavement. The firelight glistened on their spilled blood. The criminals had left terror and destruction behind them. And this spectacular crime, in the very shadow of police headquarters, staged at a time when the commissioners’ conference was in session, seemed a mocking gesture — a bloody challenge to the forces of the law.

Chapter XIII

SECRET AGENT “X” slipped away into the darkness. No use looking for clues around the brokerage office where the raid had taken place. Seething flames were consuming the entire interior of the building. All evidence would be destroyed — even the method used in blowing the big safe.

And “X” wanted to escape further contact with the members of the commissioners’ conference. Neither Foster nor Professor Beale would forget that he had refused to show his fingerprints. As Baldwin he was a marked man now.

He looked at his watch. Ten o’clock. Signaling a cab, he drove to within a few blocks of his nearest hideout and once again changed his disguise to that of A.J. Martin.

Next he called the rooming house occupied by McCarthy, the old ex-dick who was watching the airport from which “X” had been kidnaped the night previous. But the wheeling, crack-voiced landlady told the Agent she had not seen McCarthy all day. A slight frown of worry between his eyes, “X” drove to the rooming house. Perhaps McCarthy had left a message for him.

The landlady admitted him and he went straight to McCarthy’s room. But there was no message, no sign that McCarthy had been in that evening. The ash tray was empty, just as the landlady had left it. The bed had not been slept in. McCarthy was evidently making good his promise, giving the man he knew as A.J. Martin his money’s worth. He had been on the job of watching the air-field for twenty-four hours. He was still on the job, unless—

Agent “X” sent the V-shaped nose of his roadster plunging toward the suburbs. It was strange that McCarthy should have stayed on the job so long without sending him any word.

He came to within a quarter of a mile of the lot from which he had taken off in the tri-motor, a prisoner of the criminals. He passed by a row of run-down houses, came to the edge of the lot itself. It was a desolate place of refuse and junk. A lean, green-eyed cat slunk out of his path. Somewhere a loose piece of roofing on one of the buildings around the lot squeaked mournfully in the wind. This was the only sound. The cat was the only living thing.

A sense of definite foreboding gripped the Secret Agent. He moved forward cautiously, wraithlike in the gloom, coming at last to the spot where he had stationed McCarthy.

Flashing a tiny light with a bulb no larger than a grain of wheat he stared at the ground. In one spot his sharp eyes detected McCarthy’s footprints. Here were the wide heavy soles that the old dick wore. Agent “X” gave a low whistle, listened. If McCarthy were about he would come to investigate. Expert and silent shadower as the ex-detective was, he would make a noise that the Agent would hear. But there was no sound.

The Secret Agent’s sense of uneasiness grew. He moved along the edge of the lot toward the old building which might conceivably have housed the big plane. Once again he flashed his light and spotted McCarthy’s footprints. Then suddenly he stooped and tensed. Something dark showed against the brownish dustiness of the earth.

The Agent bent down, cupping his hand over the end of his small light, examining the spot on the ground. It was a circle, its coloring gruesomely suggestive.

He moved his light, found another spot a few feet farther along. His eyes were grim now. These spots were unmistakable to his experienced eyes. They were drops of blood, sunk into the ground, dried. They seemed to be about twelve hours old.

He bent all his efforts to following them now. Once he lost them among sparse turf. In patient, ever widening circles he located them again. A chill ran across his skin. Here were not only the drops but parallel grooves in the dirt; plainly discernible. His movements quickened as he followed these. They led in the direction of a cluster of sheds. The human body had been dragged there.

The grooves ceased, but drops of crimson marked the trail. Some one had picked the body up, carried it. The spots on the ground led to a pile of old boarding between the two sheds. There they ended.

Lips compressed in a tight grim line Agent “X” began shifting the boards. He swore at last, and bent sharply. The last board he had picked up disclosed the head and shoulders of a man.

White hair gleamed like silver under the thin rays of his flash. The still features of a white face showed. It and the hair were streaked with crimson. It was McCarthy — dead.

SOME one had sneaked up out of the darkness and bashed in the detective’s skull with a vicious blow. Some one had dragged the old dick here, buried him like carrion under a pile of boarding.

The Agent’s fist clenched. Out there under the dim light of the stars he made a silent pledge. Then he stopped, searched McCarthy’s pockets. The fifty dollars that he had given McCarthy was still intact. No robbery had taken place. McCarthy had been killed merely because some one wanted him out of the way. Again Agent “X” saw the hand of the man whose mark was a loathsome Octopus.

Carefully he gathered the old man up, carried him to his parked car. His eyes and ears were alert for any movement in the darkness. But there was none. The lurking criminal, or criminals, who had done the detective to death might be miles away now. Knowing the field was under suspicion there would probably be no more activity from it.

“X” drove McCarthy back to the rooming house, told the landlady in a few words what had happened. While she went to notify McCarthy’s nearest relative, Agent “X” drew his wallet from his pocket. He took out a sheaf of bills totaling nearly two thousand dollars. Lifting McCarthy’s keys from his pocket, “X” unlocked the old detective’s battered strong box.

Inside were a few yellowed letters written by his dead wife. A tarnished badge he’d worn for years as a cop; an old police whistle hallowed by association.

Agent “X” stuffed the bills in here, locked the box again. This money would go to his beloved grand-children. McCarthy would be pleased if he could know it.

“X” did not wait for the arrival of McCarthy’s relatives. There would be a police investigation into the man’s death. He couldn’t afford to have the name of A.J. Martin mixed up in that. And the death of McCarthy had made him think at once of Sloan, his agent in Boston.

He hurried to a telephone booth, put in a long distance call. The heavy voice of his Boston operative answered and “X” gave a sigh of relief. The responsibility of one man’s death rested on his shoulders tonight. He was glad it was not two.

“What’s the report, Sloan?” he demanded.

“Nothing much, boss,” Sloan answered. “It don’t look like there’s anything phoney about this bird Van Camp. He’s got an office down on Tremont Street. He spent most of the day there, lunched at his club. He was in court a while this afternoon. Tomorrow he’s flying out to Chi. He booked his passage today.”

Agent “X” was careful to hide the excitement he felt. Van Camp flying out to Chicago. With crimes being perpetrated in every state of the Union, it was plausible to think that the evil genius who directed them would have some central headquarters. Chicago would be a logical place — and now Van Camp, on the heels of his significant phone call to Tasha Merlo, was going there. Here was a hot lead.

“Thanks, Sloan,” “X” said. “I guess I was wrong about that bird.”

“You want me to trail him some more when he gets back?”

“No, not unless I give you the high sign. What time is he leaving tomorrow?”

“The plane takes off at eight thirty, boss.”

AGENT “X” hung up. Sloan was a good shadower; but he was too slow moving and slow thinking to be of much help against such men as the Agent was going up against. Yet if “X” went to Chicago he’d need aid perhaps; and it would be better to import a helper unknown to the Chicago underworld.

“X” took from his pocket a notebook in which he kept the names of several possibilities, flipped the pages intently, then paused and nodded. James Hobart was the man he wanted. Young, alert, fearless, Agent “X” knew Hobart to be honest, even though a black cloud of disgrace now hung over his name. Hobart had been dishonorably discharged from the police force after it was proved he had accepted bribes in a famous racketeering case.

Because he knew Hobart’s calibre, the Agent had made secret investigations. These had revealed that Hobart had been framed by a notorious gangster. His dismissal had been accomplished because he was becoming a source of danger to the gangster in question.

“X” got into his roadster. At Hobart’s address, a pleasant-faced, gray-haired woman let him into a small neat apartment. A raw-boned young man sat slouched in a chair, reading a paper. A stiff crest of reddish hair surmounted his forehead. Clear blue eyes lighted at sight of Agent “X.” He thrust out a freckled, big-knuckled hand, gripped the Agent’s.

“Hello, Mr. Martin…. Mom, this is Mr. Martin, the big newspaper guy I told you tried to pull strings and clear me when I was framed by Madder.”

Agent “X” smiled at the ex-detective’s mother. He gazed approvingly at the young man. He’d thrown a couple of small jobs Hobart’s way. The job he had in mind now might call for everything the boy had. But before Hobart’s career with the police had been abruptly ended, his promotions had come quickly because of his bravery and energy. Here was a man who could be depended upon in any emergency.

When the young man’s mother had gone into the kitchen Agent “X” spoke quickly.

“How are things going, Jim?”

“Not so good, Mr. Martin. No job. I was cut out to be a dick, I guess. I don’t seem to fit in anywhere else.”

“You wouldn’t turn down a job then, I take it?”

“A job — say! I’d turn handsprings from here to Kalamazoo to get one!”

“Supposing it was dangerous?”

Hobart laughed with a tinge of bitterness. “Remember I was a police dick once, Mr. Martin. I used to get into some tough spots. For two bits right now I’d play dentist to a lion with the toothache. That’s how bad I need a job.”

“I’ve got one for you,” said the Agent quietly, “that may make a lion with a toothache look like child’s play. Want it?”

“Do I want it! When do I start?”

“Seven o’clock tomorrow. I’ll stop by for you on the way to the field.”

“Field?”

“Yes, we’re going to fly out to Chi in the morning.”

THE Agent’s Blue Comet was still in a hangar on the Boston airport. It was the other of his two ships that the mechanic wheeled out the next morning. This was a trim swift cabin monoplane that would comfortably seat four people. Gas could be stored in the extra place if the necessity arose. It was capable of long-distance cross-country hops. Streamlined outside, the interior was as luxurious as a limousine. The Agent had use for both types of ship in his varied and dangerous work.

Jim Hobart’s eyes popped when he saw the plane, and realized for the first time that Agent “X” was going to fly it.

“I didn’t know you were a pilot, Mr. Martin — and I didn’t know you owned a bus like this.”

“Live and learn,” said Agent “X” quietly.

The ex-dick’s eyes were shining. Agent “X” smiled. He hadn’t done wrong in picking Jim Hobart. Here was a fellow who was ready for anything.

The plane took off from the field with the swift grace of a bird. This ship was orange and black. Agent “X” called it the Oriole. It was almost as speedy as the Blue Comet. Its cowled radial motor developed a maximum four hundred and fifty horsepower. The cabin fuselage contained numerous gadgets not apparent to the casual eye and not possible in an open-type ship. There were oxygen tanks for extremely high altitudes, a heater to make the cabin comfortable in winter cold, a special compartment in the rear for a gyroscopic stabilizer and an elaborate radio sending and receiving set.

There had been no other ships on the field as he took off. But, fifteen miles out of the city, “X” looked down and saw another swift plane rising from what appeared to be a bit of pasture land below. It climbed swiftly, displaying speed and power, stayed parallel for a short space; then struck off at a tangent. In ten minutes it was a mere speck on the horizon. A moment later it had gone.

Mile after mile reeled off below them. He swung over to the silver ribbon of the Hudson, followed it up to Albany, cut across toward Syracuse. The swift ship seemed to devour space. He knew he would be in Chicago long ahead of the passenger liner bearing Van Camp. He intended to be at the airport when the commercial plane landed.

Hobart sat alertly beside the Agent, asking an occasional question regarding the operation of the ship. Once Agent “X” demonstrated how his gyroscopic stabilizer could fly the plane level with no hands on the controls. Hobart nodded appreciatively as the swift ship flew itself. Agent “X” switched off the stabilizer, sank back into the luxurious leather-padded seat in front of the instrument board.

Then, out of the sunlit morning sky, the shadow of death came quickly, riding like some evil-visaged vulture of doom.

Something struck the cabin of the Oriole as if lightning had forked from that serene blue sky. A crackling, smashing lance of destruction passed through the swift plane’s roof. Splinters of metal, fabric, rained upon the shoulders and heads of Agent “X” and Hobart. The lightning-like lance, thrust by death’s quick hand, smashed on down through the ship’s rubber carpeted floor, making unsightly holes.

It was the Agent’s deft touch on the controls that saved them in that first perilous moment.

He thrust the rubber-knobbed stick sidewise, kicked the rudder pedal as far as it would go, threw the plane into a wingover that almost snapped Hobart’s head off his neck. The monoplane corkscrewed through the air. As it did so, fiery tracer bullets probed for it. In the sky above, a dark-winged biplane dived at them and, on the biplane’s nose, behind the whistling propeller arc, a brace of synchronized machine guns chattered and danced with the insane, ghoulish cackle of a destroying idiot.

Chapter XIV

HOBART swore fiercely, shouting a question. There was no time for Agent “X” to answer. The vicious cackle of the flying lead had stirred old memories in his mind. He’d been a youngster in the grim red days of the World War; but a youngster who had ridden the flaming skies, tramped through shell-torn trenches, played at death in a hundred different ways, pursuing the desperate missions of the Intelligence Service.

Agent “X” side-slipped. The bright orange monoplane seemed to drop toward earth on one wing. He pulled it out of the slip, dropped its nose for a moment, picked up roaring speed in a short power dive. But again the feathery lines of the tracers came dangerously close.

He suddenly drew the stick back into his lap and sent the nose of the monoplane hurtling almost straight up to the clouds. Hobart, unused to aerial acrobatics clutched the sides of the seat with all his might. But the sheer speed of the plane seemed to counterbalance gravity.

Agent “X” let the ship mount till it was on its back at the top of a loop. Then he did a sudden wing-over again, straightening out at a higher level, headed in the opposite direction.

Now he got a glimpse of the attacking ship. It was a dark-winged biplane, rakish, sinister. There were two cockpits; but it seemed as fast and maneuverable as a pursuit ship. There were machine guns in the rear pit, too, and he could dimly see two heads, faces hidden by goggles. Here was more evidence of efficiency and organization. This plane was equipped solely and obviously for the bloody business of murder.

It came thundering straight down out of the sky again. The Oriole was unarmed. The men in this dark ship meant to destroy it. “X” had only the mechanical perfection of his own plane and his skill and wits to depend on.

For a brief second he looked up. There were sweeping cirrus clouds far above him. Those clouds would afford protection if he could reach them. But the men in the other plane seemed to divine his thought. They laid a barrage of deathly steel-jacketed bullets across the sky. The attacking ship still had the advantage of altitude.

Agent “X” was too wise in the methods of air combat to try to escape by diving. That stubby-winged biplane looked as though it would have an edge over him in a drop. He’d seen many a novice during the war go to a flaming death trying to dive away from an enemy.

Agent “X” headed toward the other plane, bored steadily forward till the lines of the tracers came dangerously close.

The two planes were rocketing toward each other with cometlike speed. Bullets lashed the tip of the Oriole’s right wing. Once again “X” side-slipped away; then screamed down and up in an outside loop that threatened to tear the wings from the ship. When he was level again he continued to climb, the throttle pushed forward to the quadrant stop.

But the dark biplane possessed stupendous climb also. It pulled out of its dive, soared up on stubby wings, turned and relentlessly followed.

“They’re killers, Mr. Martin,” screamed Jim Hobart hoarsely. “It looks like a tough spot. What do you figure it means? Who are they?” His voice rose above the droning blast of the engine.

Agent “X” answered grimly.

“Part of a gang I’m trying to get a line on, Jim. They must have been doing some snooping of their own, found I was interested in them and figured I was going to Chi. That’s where their headquarters are.”

“Gangsters from Chi,” muttered Hobart. “I thought the end of prohibition had put a finish to their racket.”

“This is a bigger racket than alky ever thought of being, Jim. You’ll get a line on it if we—”

The sinister crackle at breaking glass interrupted his words. A burst from the plane behind had side-swiped the cabin of the Oriole, shattered a window. Cold air streamed in. The Agent’s eyes blazed. Then he gave a sudden exclamation. For a tongue of flame was licking the inside of a partition between the two windows. Incendiary bullets.

THE flame threatened to catch the plane’s cloth-covered interior, whipped on by the wind that was coming through the broken window. “X” dropped the control stick an instant, snatched a small extinguisher from beneath the instrument panel, and sent a hissing jet of chemical toward the burning spot. The flame went out; but the rat-tat-tat of the machine gun sounded again.

Grimly Agent “X” set himself to avoid those probing bullets. The men behind him knew their job. Their ship seemed as fast as his. A few incendiary bullets through the wings, and their own plane would become a flaming inferno. He was amazed that the gang he was fighting was aware of his intention of going to Chicago. It proved that the Octopus had a thousand eyes as well as a thousand sinister claws.

A smudge of smoke on the horizon showed now. Chicago! It wasn’t more than twenty miles distant. A sudden gleam came into the Agent’s eyes. Following the mysterious instruction of the Octopus, men were trying to kill him. He was to be wiped out before Van Camp arrived in the city, before some sinister meeting of the criminals took place. Perhaps the only way he could avoid suspicion was to appear to die.

For a second he cut the motor, talked quickly as the plane fell in another swift side-slip.

“I’m going to gamble, Jim — let them think they’ve got us. It’s the only way. When we hit, get away from the ship as fast as you can and keep under cover.”

“You mean — you’re going to crash?”

Agent “X” nodded grimly. He was fighting a crime corporation capitalized for millions, fighting men who stopped at nothing to achieve their sinister purposes. He stood ready now to sacrifice the Oriole, a ship that had cost altogether eight thousand dollars. But the vast resources given into his hands had been for the purpose of combating crime. Money was no object if the spending of it would bring criminals to justice.

As though he were wounded, or as though something had happened to the mechanism of the ship in that last burst. Agent “X” threw the Oriole into a series of erratic maneuvers. These were cunningly calculated to save them from the probing bullets of the plane behind as well as to lose altitude.

He dropped the nose into a sickening spin, making sky and ground below mingle in a mad, dizzying scramble. White-faced, but game to the limit, Jim Hobart clung to his seat, strained against his safety belt.

Agent “X” knew without looking that the other plane was following, ready to administer a coup de grace when he straightened out.

He jerked the monoplane out of the spin, but instantly, as incendiaries screamed close to his wings, he pulled the plane’s dive into the beginnings of another loop. At the top of it he seemed to lose all control. The orange ship dropped off on one wing, swept downward as though strung on a giant pendulum. From side to side it swept in a series of breath-taking plunges, like a dry leaf fluttering earthward.

And, as it lost altitude, Agent “X” reached under the instrument board and pulled toward him the handle of a small lever. There was a hiss, a roar, and instantly the air behind the plunging plane was filled with dense black smoke. It seemed that the incendiaries had fired the ship.

Hobart, not catching the significance of “X’s” tug on the lever, jerked his head around, eyes aghast. For the sky behind them was veiled in a pall of smoke.

“We’re afire!” he yelled, above the rumbling of the motor. But Agent “X” shook his head, pointing to the lever.

“That’s what I want them to think!” he said.

He had loosed a chemical into the feed line which came back through the engine exhaust in this dense, black vapor. Like the “smoke pots” used in movie shots of aerial warfare, it gave the effect of fire.

HE sat at the controls tense-faced now. The realistic crash landing he planned was a death-defying trick. Below were open fields interspersed with clumps of second-growth trees, their green tops feathering in the morning breeze.

The Agent opened a small trap in the floor, stared down. A deft touch on the ailerons, and the plunging plane slipped more to the left. Agent “X” calculated the distance down to the last foot. Above, ready to administer more leaden death if he should pull out of the aerial contortions that seemed the plunges of a doomed plane, was the other ship. He could faintly see it through the swirling plumes of smoke.

He let the Oriole side-slip swiftly toward the woods, judging the height of the trees. The wind was singing a devil’s paeon in struts and wires now. Agent “X” yelled to Hobart.

“We may have a bad crack-up. I’m going to take a chance. Don’t forget — get out of the plane as soon as we hit.”

Agent “X” did not elaborate; but he had a reason for his words. He wanted to make their crash as conclusively realistic as possible.

At the last second, as the ship swooped toward the woods, “X” brought the nose up to kill air speed. The orange plane “mushed” down among the pliant trees. Automatic wing slots opened up and checked the speed still more. The plane settled on the tops of the trees. Its weight tore branches. The weight of the engine pulled the nose down. It plunged into the green sea of foliage like some sea monster sinking below waves.

Branches made a terrific racket against the sides of the cabin fuselage. The light of the sky was blotted out by the green darkness of the leaves. Agent “X” had cut the switch. He braced himself, shouted to Hobart as the plane finally struck the ground.

There was soft forest loam here. It acted as a shock absorber, checked the concussion of the plane’s fall. With a grinding, cracking series of bumps the plane came to a standstill.

Agent “X” unsnapped his safety belt, kicked the side door open.

“Out — quick!” he said.

The lanky Hobart tumbled onto the forest floor. Agent “X” grabbed his suitcase, pitched it out ahead of him, then reached under the plane’s instrument panel again. He threw a small, inconspicuous switch. A faint noise like a concealed buzzer sounded somewhere inside the engine cowling.

Agent “X” tumbled out after Hobart, grabbed the ex-dick’s arm. “This way! Run!”

Under cover of the trees, while the black plane circled low overhead, they plunged forward across the forest floor. Fifty feet and Agent “X” suddenly pulled Hobart down on the ground, flat on his face.

As he did so there was a roar behind them. A mighty wind seemed to howl and shriek through the branches. The slender wings and gleaming fuselage of the Oriole blew into a myriad pieces as an electrically discharged time bomb exploded in the interior of the ship.

Chapter XV

THE terrific blast of the bomb was followed by a second of silence. Then bits of metal from the shattered plane rained down making a spatter like hail on the trees. The motor whine of the dark ship was plainly audible. It was circling overhead.

“Don’t move!” hissed Agent “X.”

The biplane dived low, so low that its tail assembly almost fanned the foliage that concealed them. Three times the plane circled. Then the drone of its motor faded into the distance.

“God!” breathed Hobart. He wiped sweat from his face, turned wide eyes on “X.” “There must be something big going on, Mr. Martin. They tried to knock us out of the air. You cracked up a plane worth more dough than I’ll ever have if I live to be a hundred. What the hell’s it all about?”

“I don’t know exactly myself, Jim. I flew out to Chi to find out.”

“Did the paper send you or did you come on your own?”

Secret Agent “X” smiled, tapped the lanky ex-dick on the shoulder. “Don’t ask too many questions.”

Hobart’s steady eyes met “X’s.” He flushed, spoke with quiet vehemence. “I ain’t trying to stick my mug into your affairs, Mr. Martin. Any dope you want to hand me, O. K. But you’re the boss — and I know you’re on the level. All you gotta do is tell me what to do, and you can count on me to do it. I’d just like to get a line on who these damn killers are.”

The Agent rose, faced the other soberly for a moment. “Those men up there were small fry, Jim — just paid gunmen. Get that. Somebody hired them to do a job. It’s that somebody I want to get the low-down on.”

Jim Hobart nodded, dusted loam off his clothes, and followed as the Agent struck off through the woods, suitcase in hand. “X” was careful to keep in the thickest cover till they were a good distance from the spot where the Oriole had crashed. He turned suddenly on Hobart.

“We’ve got to get to Chi now. Those birds think we’re dead. They’ll report to their boss that they got us. That gives us the start on them.”

There was a highway about a half mile from the spot where the Oriole had blown up. Cars lined it and several men, attracted by the noise of the explosion, were running across the fields to investigate.

Agent “X” turned and walked in the opposite direction, motioning Hobart to follow. At the end of half an hour they came to another road leading into Chicago, followed it to a suburban village and there chartered a taxi.

“X” directed the driver to one of the better known hotels in the heart of the city. He spoke quietly to Hobart as the cab rolled through the streets.

“We’re a couple of traveling salesmen from New York, Jim. Your name is Calvin Prentiss, mine’s B.J. Morgan. Those are the monikers we’ll sign on the register.”

“You should have been a dick instead of a news shark, Mr. Martin,” said Hobart admiringly. “You’d have been a wow.”

A grim smile twitched the corners of the Agent’s mouth. The cab drew up before their hotel.

“Remember,” he said. “Calvin Prentiss and B.J. Morgan.”

It was a big hotel, popular with transients. Agent “X” engaged adjoining rooms under the names he had mentioned to Hobart. He looked at the clock. The plane from the East, bearing Van Camp, was due to arrive in Chicago in about an hour. That would give him plenty of time to get out to the airport; but there were certain things to be done first.

HE started toward the elevator with Hobart at his side; then paused and glanced quickly across the lobby.

His fingers dug into Hobart’s arm. He spoke without moving his lips; spoke so softly that the ex-dick alone could hear. “Take a look at that woman over there, Jim — the one in the green dress, sitting on the left side of the column. Don’t let her see you.”

“I get you, boss. A swell looking dame! I’ve always heard there was plenty of fast steppers in Chi.”

“She isn’t from Chicago. She must have arrived here yesterday or today. We’re in luck.”

“You can have her, boss. I’m a redhead myself, and I’d rather play around with a blonde, or maybe a nice little brunette.”

“Sorry, because I’m going to turn her over to you, Jim.”

“Say—”

Secret Agent “X” motioned for silence as they entered the elevator. When the bellhop had shown them to their rooms, Agent “X” spoke quickly, tensely.

“That woman, Jim — her name’s Tasha Merlo. She used to be one of the cleverest fences in the East. Now she’s doing something else. Your work’s cut out for you. I want you to find out where she goes, who she talks to and what she does. Don’t lose sight of her. But be on your guard every minute. She’s poison.”

“You know her then, boss?”

“I do; but she doesn’t know me.” “X” laid a hand on Hobart’s arm, added a sudden word of caution, remembering certain tendencies that Hobart had. “Don’t try to make up to her, Jim. Just keep her in sight — and you’ll need every trick you ever learned on the force.”

“O. K.,” said Hobart. “But I thought you said you was trying to get a line on the gang who hired those killers to knock us down.”

“I am, Jim, and this woman’s with the gang. Now do you understand?”

Hobart’s young face hardened. “I savvy, boss. Fly paper won’t have nothing on me when it comes to staying glued to that jane.”

“Good. I’ll see you here again at noon — or if not then, at six. If you don’t get a chance to come back to the hotel send me a telegram — B.J. Morgan.”

“Where are you going, boss?”

“Places.”

With no further explanation, Agent “X” left, removing a brief case from the suitcase and taking that with him. He took a taxi to a small, old-fashioned apartment, let himself in with a key on his ring. Here was another hideout, established many months ago.

In the privacy of this he changed his disguise quickly. If A.J. Martin had been traced to the airfield where he had that morning taken off, then A.J. Martin was no longer an adequate disguise against the members of the Octopus organization. The criminals thought that Martin was dead in the crash of the Oriole. “X” would let him stay dead so far as they were concerned. The dark-haired, solemn-faced young man who emerged under his skilled fingers was utterly different from the brisk looking, sandy-haired Martin.

Changing his suit to another in the closet of his hideout, he left the apartment and took a taxi to the airport.

Sloan in Boston had given him an exact description of Van Camp. When the big tri-motor passenger plane landed on schedule, Agent “X” had no trouble identifying the lawyer.

THE man was quite thin, stoop-shouldered, with graying hair and deep-set gray eyes that glowed piercingly behind thin-rimmed glasses. He was a man with a poker face, a man whose high cheek bones had the set rigidity of an Indian’s.

The Agent’s pulses tingled. Unless he was mistaken he was looking at a member of the mysterious Octopus’s gang. Or was Van Camp himself the Octopus? There was as yet no way of telling. But that he was connected with the strange stock promotion scheme Agent “X” had sufficient proof.

Van Camp signaled a taxi, got in, and left the field. Agent “X” followed in another cab. The lawyer went directly to one of the most expensive Chicago hotels. Agent “X” strolled into the lobby a moment later. He saw a bellhop start toward the elevator with Van Camp’s luggage, saw Van Camp himself receive some mail from the hand of the desk clerk, proving that he had made reservations in the hotel before he started this morning. Van Camp pocketed the mail, followed the bellhop into the elevator.

Secret Agent “X” strolled by the desk, letting his eye fall on the open register. He got Van Camp’s suite number, 806, strolled on through the lobby to a waiting elevator. There was no time to lose. The grilled door clicked shut as he stepped into the car.

“Eight, out,” he said.

When he emerged in the eighth floor corridor the bellhop who had shown Van Camp to his rooms was just leaving. “X” watched him enter a descending elevator, leaving the corridor empty. Quick as a flash, Agent “X” went to the door marked 806.

His kit of chromium tools was already in his hands. But he put it away when he saw the lock, took out his key ring instead. On it were six fragile skeleton keys of assorted sizes. One of these would do the job.

So deftly and softly that there was barely a scrape, he tried two keys. The second one fitted, turned in his hand. The door opened.

Van Camp had taken one of the hotel’s more pretentious suites. “X” had figured on this. There was a hallway, three rooms opening off it. In the farthest of these was a light, the shadow of a man on the wall. Silently Agent “X” ducked into the nearest darkened room. His gas pistol was in his hand. He waited, heard the rustle of paper. Van Camp was opening his mail.

When he had finished he walked to the telephone. The number he called was that of the hotel where Hobart and Agent “X” had registered an hour before. Van Camp’s voice was well modulated, but slightly nasal.

“I’d like to speak to Miss Tasha Merlo, please.”

There was an instant of silence, then the lawyer spoke rapidly.

“This is Van Camp, Miss Merlo. Remain where you are until I call you again. You are to act under my instructions. A new territory will be assigned to you, possibly in the West. The matter which you called to my attention has been taken care of. It was troublesome; but gave no serious cause for alarm. Because of your promptness and efficiency in handling the matter I shall recommend you for promotion at our meeting tonight. That is all.”

The receiver clicked up, terminating the conversation. But the Agent’s pulse beat had increased. The lawyer’s matter-of-fact words had told him several things. The most important was that there was to be some sort of secret meeting tonight in Chicago. The “matter” which Tasha Merlo had brought to Van Camp’s attention was in the Agent’s mind undoubtedly his own visit to her house. It had been “taken care of” when two killers had been engaged to shoot him out of the sky. Did this mean that Van Camp was the Octopus?

THEN the lawyer phoned again. This time the conversation seemed more cryptic than before.

“All our directors will be there, I understand, Mr. Harding. The same place at the same time. No, nothing serious. Yes, a very good gesture. It should promote interest and faith substantially.” Van Camp’s laugh sounded, a strange, dry chuckle.

The receiver clicked up a second time. Van Camp broke into a tuneless whistle. Agent “X’s” thoughts raced. A board of directors. A chairman. Van Camp then was only one of several directors. But the place where the meeting would be held had not been mentioned. And if he waited and followed Van Camp this evening it might be too late.

One of the fantastically daring plans that made Agent “X” an investigator extraordinary formulated in his mind. Gas pistol in hand, he walked softly along the hallway. He was in the very doorway of the room where Van Camp was, before the lawyer turned and saw him.

An expression of utter amazement made Van Camp’s face muscles sag. Then, with a movement fast as the head of a striking snake, the lawyer reached toward his open bag.

“Don’t,” said Agent “X” harshly. “Lift your hands, Van Camp.” The muzzle of his gas gun emphasized the command. The tone of his voice was unrelenting. But it was the strange, piercing quality of the Agent’s eyes that seemed to hold Van Camp spellbound, as though they radiated a force and magnetism which the lawyer could not combat. Slowly his hands went up. The gaze that he fixed upon the Agent was like that of a cornered rat.

“What — what do you want?” he gasped.

“A little information,” said “X.” “Just where is this directors’ meeting you came to attend tonight, and what time does it take place?”

All color drained from the lawyer’s face. The skin seemed to tighten along his cheek bones till his head looked like a skull.

“Who are you?” His voice was so low that it barely whispered through the still air of the room.

“Never mind — answer my questions.”

Van Camp’s lips pressed together. Slowly he shook his head. He waited rigidly like a man who expects death, a man who knows there is no possible alternative. For long seconds Agent “X” stared into his eyes.

“You will not speak. You are afraid of the Octopus!”

The words only deepened the deathly look on Van Camp’s face. Agent “X,” a masterly judge of human actions, knew that here was a man whose lips were sealed by a fear so great that no threat could open them. Fear would not make him babble like the craven Quade. He knew more than Quade. For that reason he would say less. Agent “X” acted quickly.

His finger tightened around the trigger of the gas gun. A jet of vapor spurted into Van Camp’s face. His body sagged, and he fell soundlessly to the floor. To all intents and purposes he was dead; but the effects of the gas pistol would wear off in twenty minutes. Van Camp would then be himself again.

Agent “X” went through the lawyer’s luggage quickly, studied everything in his pockets including the mail he had received. There was nothing which could in any way prove that Van Camp was other than he appeared — a respectable, hard-working criminal lawyer.

Agent “X” had half expected this. The brain behind this criminal was too clever to let any member carry incriminating evidence. But “X” had come prepared. Knowing that all depended on finding out Van Camp’s connection with the stock-selling scheme, he had brought an instrument of investigation which he seldom used. This was a bottle of small greenish capsules; a preparation of that drug known to the medical profession as sodium amytol. The Agent knew its history. It had been used successfully in psychopathic clinics. Often it was used in place of ether as an anaesthetic for minor operations.

It had a peculiar effect similar to that of hypnosis. The patient, with no sensation of pain, no consciousness that he could remember after he awoke, would answer truthfully questions put to him. This was why psychiatrists had employed it to get at the root of fixations in their patients’ minds.

“X” poured a glass of water, lifted Van Camp’s head, deposited two of the capsules on his tongue and made him swallow them. He propped Van Camp up on the sofa, looked at his own watch. In a matter of twenty minutes he would learn the location and time set for the Octopus’s strange board of directors’ meeting.

Chapter XVI

THAT night a man who appeared to be Van Camp drove along Roosevelt Road. He was headed toward the suburb of Cicero, a peaceful section of manufacturing plants, homes, schools, churches. Once it had been the scene of the bloodiest gangster battles in American history. Swaggering overlords of crime, in the palmy days of prohibition, had ruled here until underworld bullets cut short their careers. The faces of many buildings were still pock-marked with machine-gun slugs. Citizens could still point to the precise spots where famous racketeers had dropped in their tracks.

Secret Agent “X” had obtained the information he wanted from Van Camp. He had learned where the meeting of the Octopus’s strange band was to take place. He had learned the time schedule, memorized the mysterious passwords and signals. Now, disguised daringly as Van Camp, he was on his way to face death.

Down a dark side street, away from the business section of Cicero, he turned the nose of his hired, drive-yourself car. He went four blocks, parked, and got out. The night seemed peaceful. Stars winked overhead. A faint warm breeze stirred the branches of the few trees along the street. But somewhere not far ahead the masters of sudden death were meeting.

Secret Agent “X” went another two blocks on foot, following directions which he had wrung from Van Camp’s lips by means of the drug.

He came at last to a group of deserted buildings which sprawled across the space of a whole city block. A high barbed-wire fence encircled the property. It was a group of factory buildings formerly owned by an electrical company. Posted signs warned trespassers off and gave notice that the property was now in the hands of a real estate holding concern. When business conditions warranted it, these buildings would be salvaged or torn down and others erected. Now they were as still and bleak as huge mausoleums.

Agent “X,” eyes glowing bright, walked swiftly along the opposite side of the street parallel with this old factory site. He paused when he saw the dusty windows of a small cigar and stationery store ahead. A faded sign in gold lettering bore the words “Colosimo Rici.” The front of this store faced the main entrance of the closed factory. Agent “X” glanced at his watch, nodded to himself, strolled into the store.

A chair creaked in the rear. A greasy-faced proprietor came waddling out to the counter. The man had eyes as black as agate hidden in rolls of baggy flesh. His skin had a toadlike wartiness. He crouched over the counter, staring at Agent “X.”

With no change of expression the Agent made several purchases. He ordered three packages of cigarettes, all of different brands. Carefully, under the eyes of the watchful proprietor, he opened one of the packages, took out a cigarette and lit it. Three puffs and he broke the cigarette in half, dropped one half on the floor, tossed the other behind the counter.

The proprietor gave a barely perceptible nod.

“Wait,” he said gruffly.

He came around the counter, waddled to the door of the shop, looked up and down the street in both directions. Then he re-entered and tapped Agent “X” on the arm.

“You like a little drink, Mr. Van Camp?” he said.

“Make it two fingers straight, Piere.”

“Go in and help yourself.”

A simple but effective exchange of signals and passwords had been made, secrets learned from the lips of Van Camp.

Agent “X” walked to the rear of the dirty little store. He opened a door, walked straight along a short hallway, entered a small back room. There was a table and several chairs in the center of this. On the back wall was a shelf holding liquor bottles and glasses. It seemed a place where Piere, the fat proprietor, could receive a few intimate guests in private while waiting for customers in his small shop. Nothing more.

But Agent “X” walked directly to the shelf of bottles and glasses. He paused a moment, eyes questing. His hand reached beneath the shelf, fingers groping along its under surface. Concealed there, where no one would ever think of looking, was an electric button.

The Agent pressed it. A moment of silence, then a faint clicking sounded somewhere behind the shelf. He seized the edge of it, pushed to the left. It moved ponderously revealing itself as a heavy steel door on rollers.

Behind it was a landing, and a flight of dark stairs leading down with another door at their bottom.

NOT until the shelf had rolled back into place did an electric bulb over the door below light up. When Agent “X” reached the bottom of the stairway, the door swung open as though ghostly hands were upon it. It closed after him. He turned sharply to the right, then right again, till he was in a passage below street level. This led in the opposite direction from the one taken when he entered the store.

In semi-darkness, with only a faint light far ahead to guide him, he passed under the street and into the block occupied by the old factory site. Here another steel door loomed before him; a door set in thick concrete, reinforced with riveted steel cleats.

It was like the entrance to some fortress. In the very center of it was a small perforated disc resembling a telephone mouthpiece. The Agent stood erect, face pointed toward this disc. He spoke in clear precise tones, words and numbers that seemed to have no sense or order.

“Twenty-four. Colombia. Ninety-two. Ten.”

The consonant and vowel sounds made a series of vibrations in the diaphragm of the disc. Instantly there was a whir of geared machinery behind the steel door as an electric motor started. Then the door rose slowly, straight up on oiled bearings. It stopped, Agent “X” passed through, and the door began to descend automatically.

The skin along his scalp felt tight now. With the sliding down of that door his last contact with the outside world was gone. The elaborate maneuvers necessary to get into this place, the precautions taken, were further indications of the power and cunning of the brains behind it. As Van Camp he was about to join the secret board of directors. He was about to come into the presence of the mysterious chairman of that board — the Octopus himself.

He walked resolutely along another corridor, entered a wooden door. Grim steel and concrete now gave way to polished paneling and soft carpets. Ornamented lights lined this corridor. At the end of it was a gleaming mirror, running from floor to ceiling.

As he walked toward it Agent “X” saw his own reflection — the high cheek bones, the long face, the nose glasses of Van Camp. He moved with the same stoop-shouldered slouch. The sinister lawyer seemed to be approaching him.

But the mirror gave Agent “X” a momentary pang of uneasiness. Van Camp had said nothing about it. Why was it there? Was it purely for ornamentation, or did it serve some more subtle purpose? Perhaps it was Argus glass, he thought, opaque from one side, transparent from the other, so that unseen eyes could watch him. “X,” the perfect actor, betrayed no sign of his uneasiness.

THERE was one more door at the right of the mirror. He opened it and found himself suddenly in a magnificently furnished room. A long mahogany table ran down its center. Carved chairs stood alongside the table. Shaded lights, a thick rug, completed the furnishings. It was a typical board room such as one would expect in the offices of some great bank or business corporation.

Over a dozen men were seated in the chairs around the table. But several chairs were still empty.

Agent “X” walked forward, eyes focused on the edge of the table. Small numbers were inlaid in the mahogany. He took the chair before No. 14. He could feel eyes scrutinizing him. Not until he had seated himself did he look up. Then he laid Van Camp’s brief case on the table before him, adjusted his nose-glasses.

An amazing group of faces met his eye. Many were familiar to him. Here were famous gangsters, confidence men, gamblers. In this assembly were some of the cunningest, most ruthless czars of crime the underworld had ever produced. Big shots, each in his own line.

“Duke” Saragon, who had blasted his way to power in the beer-running days. The Belli brothers, last of a dynasty of Sicilian gunmen terrorists who had held sway in Chicago’s North Side. “Smiling” Dan Kilrain, the New York mobster. “Emperor” Lee Wong, head of a sinister West Coast dope ring, who had evaded the cleverest narcotic agents. And Benjamin Sullwell, suave, pink-faced stock promoter, operator of a chain of bucket shops, until income tax evasion had landed him for three years in the federal penitentiary.

These and others like them formed the Octopus’s “Board of Directors.” And what of the Octopus himself, the chairman? “X’s” eyes looked down the length of the table, narrowed slightly.

There was no chair at the head. Instead there was a boxlike cabinet with a paneled door in its front. It was still, sinister. What did it mean? The Agent waited, hiding his curiosity under the calm demeanor of a lawyer.

He sensed the tense uneasiness of these men around him. They seemed to know each other, but their expressions were strained, uncomfortable. They had assembled from every quarter of the country, all dominated by one sinister power — the Octopus. There was an air of expectancy in the manner of each.

A gangster next to “X” turned his head, spoke in a low-voiced whisper, afraid to raise his voice in that room, afraid that unseen ears would hear.

“If it wasn’t for the heavy dough in this racket, I’d slide out,” he said. “This circus stuff gets on my nerves — and I like to know who I’m working for.”

Agent “X” nodded. Others around the table were muttering, except the Chinaman who sat stolidly, staring before him. “X” pondered the significance of his neighbor’s speech. These men did not know who the Octopus was. This amazed him. He glanced again at that cabinet at the head of the table.

Other directors came in through the door from the mirrored hallway, seating themselves at the table. A small brass clock on the wall struck nine as the last chair was filled. The low-voiced conversation ceased. Every face turned toward that still cabinet.

Another five minutes passed. The tension in the room grew electric.

Suddenly the two panels of the cabinet opened outward. Behind them was a white screen six feet square. Below the screen the lattice work of a loudspeaker showed.

A sound like a sigh went up from those gathered around the table. Eyes blinked. Hands grew taut. On the screen the lifesize head and shoulders of a man had suddenly appeared. A mask covered his whole face. Only his eyes and month were exposed. The eyes seemed to bore into those about the table. The thin, mobile lips moved.

“Greetings, gentlemen.”

The sound came startlingly out of the loudspeaker. The mysterious chairman of the criminal board had made his appearance. The Octopus had arrived through the magic of science, the wonder of television. His image was there on the screen; but he himself was as aloof, as enigmatic as ever. There was no saying where he was, from how many miles distant the broadcast was being made.

A strange smile curved the Octopus’s lips. His dry, disguised tones came again.

“This promises to be an interesting meeting, gentlemen. Our work in the past weeks has been most gratifying. We have done well by our stockholders. We have other ambitious plans for the future. Will the treasurer, Mr. Sullwell, kindly read his report.”

SULLWELL, the promoter who had drawn thousands into financial ruin back in the boom days of ’28 and ’29, rose in his seat. He took a paper from his pocket His hands were trembling. The image of the man on the screen seemed to fill all these others with terror.

“We have five hundred thousand outstanding shares of stock at the present. Disbursements in the last quarterly dividend amounted to four million, three hundred and sixty-two dollars. A surplus of two million one hundred thousand is now on hand.”

The Octopus’s dry laugh sounded. “Our corporation is not yet a year old, but we have been able to enrich our stockholders beyond their wildest expectations. And — you will note, gentlemen — this concern is unique in not having any liabilities.”

The Secret Agent understood the irony of that. There could be no liabilities in a criminal group who took from society what they wanted. A group who plundered, murdered where they chose. The Octopus’s mocking voice went on:

“This, I say, is only the beginning. The dividends we have paid to our stockholders will serve to attract others. The capital we will eventually control will be unlimited. Already many are putting excess profits back into our company’s stock. We have ambitious plans for the future, gentlemen. We are here to consider two projects for the weeks immediately ahead. Both of them give promise of excellent returns on the money we shall invest in them. But, before we begin—” The Octopus interrupted his address to the board to laugh as though at some very good joke— “there is a little matter which must be attended to. It would be wise, I think, to settle it before we go into the intimate details of our projects.”

The Octopus paused. The board members moved uneasily in their seats. There was something dry, calculated, macabre, about the tones of that voice coming through the loudspeaker. The eyes of the Octopus were pinpoints of evil light. He continued.

“It will surprise many of you esteemed gentlemen to know that we have in our midst tonight a spy and imposter, here to learn what he can of our secrets and to bring about our downfall.”

Hoarse gasps went up from those assembled around the long table. Every man looked at his neighbor questioningly. Fear, rage, made evil distortions on the faces of the directors. Then they turned back to the image on the screen, staring expectantly.

“This spy,” continued the Octopus, “has been clever enough to learn all our passwords and signals. He has been clever enough to disguise himself as one of our most distinguished members. But a certain precaution which I insisted upon, gentlemen, completely checkmated his plans. I refer to the invisible ultra-ray tattooing which each of you carries on his chest. When he passed in front of the fluorescent mirror on his way in here even the cleverness of his disguise was of no avail.”

The harsh laughter of the Octopus filled the room. Agent “X’s” whole body had gone cold. He knew now he had stumbled into a trap; knew this master of crime had outwitted him. In the back of his mind he had been half fearful of some such thing. He remembered his thoughts on seeing the mirror in the hall. But he had not guessed it was a hidden fluorescent screen to detect invisible tattooing. No man could have guessed that. The Octopus’s cunning amounted to genius.

“The imposter I refer to, gentlemen, is seated opposite our treasurer, Mr. Sullwell, Mr. Kilrain is on his right. The learned Mr. Lee Wong is on his left. You have deduced by now that he is impersonating director No. 14—our astute legal advisor, Mr. Van Camp. What steps do you suggest that we take to convince him of his error in coming here, gentlemen?”

Chapter XVII

AMAZEMENT and fury blazed in the eyes of those around the Agent. All heads turned toward him. The calm, ironic tones of the Octopus were not reflected in the expressions of his board. Savage ferocity showed on every countenance. An audible hiss arose. A dozen men leaped to their feet, crouched over the table. Guns appeared as though by magic in the hands of most. The black muzzles pointed straight at Agent “X.” Death hung heavy in the room. The voice of the Octopus broke the strained silence.

“Preserve your dignity, gentlemen! This is no ordinary spy who comes to us tonight. Unless I am wrong he is one of the cleverest investigators in the country — a man you have all heard of at one time or another — Secret Agent ‘X.’”

The fingers of the two sinister Belli brothers tightened around the butts of their automatics. For a moment “X” thought they were going to shoot him then and there in cold blood.

“Rat!” hissed one. “Police spy!”

“You should feel flattered,” said the Octopus. “In giving us his exclusive attention for the past week he has paid tribute to our power. I suspected it was he when it was reported that a man shot down by some of our employees in a recent bank raid was later found alive by the police. I ordered that this man be captured. When he escaped by cleverly forcing our men to jump from their plane and later brought the plane to the ground himself, I knew it must be ‘X.’

“A very charming lady concurred with me in my suspicions. By a ruse this morning he made other of our employees think he had been killed in an airplane crash. Now you have the whole case history, gentlemen. What is your will in the matter of his disposal?”

“Death!” cried a dozen voices at once. “Death!” echoed those who had not spoken first. “Kill the louse,” screamed one of the Belli brothers. “Let me burn him, boss!”

A note of mock reproach crept into the Octopus’s voice.

“Gentlemen! We must not forget that we are the directors of a large corporation. Our conduct must never be unseemly. But I am glad to see that there is no dissension on this matter. Let it be conducted in the usual way. Will some one please make a motion?”

Sullwell, the evil promoter, raised his hand. “I move, Mr. Chairman, that the spy and imposter in our midst be punished with death.”

“Will some one please second the motion?” asked the Octopus.

Lee Wong, impassive until now, spoke in a sing-song voice, toneless as the slithering of a reptile’s scales. “Mr. Chairman, I second the motion.”

“It has been moved and seconded that the impersonator of Mr. Van Camp be punished with death. All those in favor say ‘Aye!’”

A chorus of “ayes” filled the room, vicious as the snarling of a pack of blood hungry wolves.

“Those not in favor please signify in the customary way.”

Dead silence followed this pronouncement; a silence in which the merciless eyes of a group of the underworld’s worst spawn glared balefully at Agent “X.” The Octopus’s lips moved. His voice was as calm as though this were a routine business proceeding.

“The motion is carried, gentlemen. Stand up, Agent ‘X.’ Perhaps your death will not be quite so — ah — drastic if you will answer a few questions.”

The Secret Agent arose; knuckles resting on the mahogany table, gaze focused on the screen in the cabinet.

“What did you do with Van Camp, and exactly how did you learn from him the passwords and signals which gained you admittance to this meeting?” asked the Octopus. “The gentlemen gathered around this table would like to know.”

“I’ve nothing to say, Mr. Chairman.” The Secret Agent’s voice had the calmness of a director making response to some dry business matter. It matched the Octopus’s even tones. But the master criminal’s laughter filled the board room. It had a gloating, exultant quality.

“I am amused and pleased, Agent ‘X,’ that you chose to come here tonight. I know how you work — for I have followed reports of your activities in the papers, and have gathered whispered rumors in other quarters. You share your secrets with no one. You do not call the police until all the groundwork has been done by you. That is clever: but it also has its drawbacks. For when you die tonight there will be no one to carry on where you leave off.

“The police, I am assured, know nothing. Confidence in your own prowess has become your undoing, Agent ‘X.’ And it will perhaps surprise you to learn that I devised my ultra-ray methods of identification anticipating that you might try to sit in on one of our board meetings. Your phenomenal powers of disguise have gained you quite a reputation.” The Octopus paused.

One of the directors muttered savagely: “Kill ’im.”

“I am coming to that. You can talk freely now, Agent ‘X.’ There’s no need to preserve stubborn silence. Your work is over. You remember the doors you came through? Until I myself unlock them with radio impulse no single member of this board or employee of our corporation can leave this building. If you should use any of your novel little devices, your various defensive weapons — they would avail you nothing. Let us go a step further!

“If you should succeed in killing every one of the estimable gentlemen around you, you would still be a hopeless prisoner doomed to death. For I have certain small devices myself which could handle the situation. In the event of a police raid, for instance, a gas more deadly than diphosgene, or dichlorethyl sulphide, will flood every crack and cranny of the premises in less than ten seconds. Let me suggest again that you answer my questions.”

The Secret Agent spoke coldly. “You have received my answer, Mr. Chairman.” “X” had guarded his secrets carefully in life. He would take them to his grave if necessary. At least he wouldn’t give this satanic man the satisfaction of triumphing in that respect. The Octopus’s voice became more harsh.

“You see that the gentlemen about you have guns in their hands and are anxious to kill you at once. If you make the slightest violent move they will do so. In many respects it would be better for you if you did make a break now and courted swift death. I am not advising you to do it; but you may take your choice. If you care to live a few minutes longer, however, keep absolutely quiet.”

The Octopus then spoke to one of his boardmen. “Mr. Sullwell, please ring for an attendant.”

The treasurer pressed a button. A man dressed in a black suit and a black shirt entered. His face was a dead, unhealthy white. His eyes like his suit were coal black and beady as a snake’s. The Octopus addressed him.

“We are about to place a member of this board under arrest. You will bring three of your colleagues at once and conduct him to room 13. Switch on the extension when you get there. I shall hold you personally responsible for the prisoner’s safe keeping.”

The attendant’s ashen face seemed to grow a shade more ghastly. He nodded, left the room at once, returning with three other black-shirted figures. Two of them held steel nippers in their hands.

They approached Agent “X,” clamped the nippers over his wrists. The other two men thrust automatics against his back. A slight movement of his hands showed him that the jaws of the nippers were cruelly toothed and would slash his wrists into ribbons if he tried to break away.

A dry laugh came from the screen where the Octopus’s image showed.

“When you arrive in room 13 you will be given one more chance to talk, Secret Agent ‘X.’ And perhaps the surroundings there will be conducive to conversational talents!”

The mocking note in the sinister voice prepared “X” for some hidden horror. He walked stiffly out of the board room between his captors. The murderous eyes of the directors followed him. He read disappointment there — disappointment that they were not to become his executioners themselves. But fear of the Octopus, observance of his slightest wish, held their instincts in check.

HE was taken through a series of corridors, passed doors marked in white numerals. His four captors said nothing as they marched him along. The Octopus had not explained to them who he was. They had the impersonal air of paid executioners.

They stopped before a door marked 13, opened it and led Agent “X” in. One of them switched on a light, and he stared in amazement at the collection of strange looking apparatus set on the concrete floor.

At first it appeared to be factory machinery. Then a coldness gripped “X”—understanding that brought with it chill horror. One of his captors walked to a cabinet mounted on the near-by wall, a cabinet like that in the boardroom. He opened the doors, snapped a switch, and instantly the head and shoulders of the Octopus appeared here also. His now familiar voice sounded. He spoke almost as though he could see the Agent.

“You see, I follow you, Agent ‘X.’ You cannot escape me! Look around you and you will observe what function this room fulfills. I know by heart every item it contains. The ingenious machine directly in the center of the floor, for instance! Those cogs and chains — that movable framework! Merely a modern version of the rack. We anticipated that punitive measures might be necessary. Also methods of making bashful or stubborn persons talk. That rack has proved itself efficient.

“By means of it the femur can be separated from the tibia — the radius and ulna from the humerus — the clavicle from the scapula. I believe you follow me, Agent ‘X’—you who are so well versed in science! I am speaking of the bones of arms and legs. Our rack can pluck them out of their sockets as easily as a woman would pluck superfluous hair from her eyebrows.”

The Octopus’s chuckle was like some devil’s whisper from the black mouth of hell. He continued, showmanlike, gloating over his exhibits.

“The medieval inquisitors gave considerable time and thought to the art of torture; but they were handicapped by their crude knowledge of mechanics and human anatomy. We have done better, I think I can modestly say. Let us take another little device as an example. The handsome statue of the lady in the corner is a development of the famous Iron Virgin of Nuremberg.

“Victims, you remember, were put inside the hollow statue — and spikes were driven through the chest, back, and lastly the eyes and ears. In our lady the spikes, driven by electric gears, move with exquisite slowness. Blindness, deafness, and eventual death, come only after hours. The victim of our lady’s iron embrace longs for the cruder but speedier ways of the 9th century.

“You see now,” added the Octopus dryly, “why my suggestion that you talk was made advisedly. I give you one half minute to decide. You will either tell the board members your name and the entire history of your career, including the method used to learn Mr. Van Camp’s secrets — or you will be given into the hands of our official torturer to die slowly and fearfully.”

Chapter XVIII

THE Octopus’s words carried terrible finality. They seemed symbolic of all the threats the Agent had received during his perilous career — the logical end toward which his life had been drifting.

As he stood tense, waiting, eyes fixed on those ghastly instruments of torture, another figure shambled into the room. This was a small, skeleton-thin man with rheumy eyes and a sickly, parchmentlike skin. The man’s lean fingers curled, extended, fluttered senselessly. He tried to speak; but only an inane babble of gibberish came from his lips.

The Octopus spoke: “Fifteen seconds, Agent ‘X’ and Waldo makes his entrance into our little drama. He has been handicapped by nature, as you can see. But he has a taste for things mechanical. His hands can operate levers and switches with surprising dexterity. He has infinite patience and is docile to orders. As a boy he amused himself by plucking wings from flies and other insects. He is a congenital sadist. And as you have guessed, Waldo is our official torturer.”

The entrance of this fearful being, was the last touch of horror necessary, the final proof of the remorseless cruelty of this criminal group.

“The half minute is up, Agent ‘X.’ You have chosen your own fate. You refused to answer my questions. You refused to address the board as a gentleman. But now you will talk. My directors shall hear your groans, your babbled confession on the rack. Switch on the board-room microphone! Put this man to torture!”

The masked face of the Octopus disappeared from the screen in the torture room as his voice ceased speaking. Waldo, tittering and mumbling, went to the glittering machine in the center of the floor, the fearful rack. Agent “X’s” captors tightened the grip of the nippers on his wrists, pulled him forward toward the instrument of torture. He could feel the pressure of the black-clothed attendant’s gun against his spine.

Never had Secret Agent “X” seemed so utterly helpless. The Octopus had challenged him to use some of his strange defensive weapons. The Agent had come tonight armed with several new ones — but in his present situation they were powerless to aid him.

The Secret Agent’s shoulders drooped as he neared the rack. His head lolled. He seemed on the point of complete collapse, overcome with dread and horror.

Then, in a movement so breathtakingly quick that even his vigilant captors were not prepared, he flung himself straight forward on his face, risking a bullet in the back.

The nippers on his wrists cut cruelly. The Agent’s fingers curled up, wrapped themselves around the arms of the two who held the steel-jawed instruments. The forward lunge of his body carried his captors off their balance. Shrieking curses, they too fell. One of those with a drawn gun fired. The hot blast of that shot fanned the Agent’s neck. The bullet plucked at the wig he wore in his disguise of Van Camp.

Ignoring the grinding pain of the jawed nippers, the Agent twisted like a netted fish, drew his knees up, lashed out with his feet, catching one of the nipper men in the chest. The man gave a choking cry, let go his hold.

Agent “X,” action superbly timed to the fraction of a second, swung his wrist and flung the loosened nipper straight at the nearest gunman’s head.

THE metal crashed against the man’s chin. He dropped his automatic, fell back. The other man fired as Agent “X” seemed about to rise; but the Agent lashed sidewise instead. This second bullet brought a hideous scream from Waldo, the half-wit torturer, directly in front of the man who had fired.

Waldo clapped a hand over his thin stomach. Crimson spurted from between clawlike fingers. He tottered away from the horrible rack.

In that one reckless, breathtaking movement Agent “X” had flung the room into mad confusion. The other attendant with the nipper still clung desperately to the Agent. “X” struck him a savage blow in the face with his free hand. This man also released his hold on the nipper. It clattered to the floor.

The other gunman was crouched now. Appalled for the moment by the fact that he had shot Waldo, he swung his gun toward “X” again. The Secret Agent flopped over twice in a movement almost too quick to follow; a movement dependent on his amazing coordination of mind and muscle.

Bullets slapped against the concrete flooring, plucked at his clothing. His own hands swept up the pistol that the first gunman had dropped. With the same movement he fired; and a shot shattered the shoulder of the black-clothed man who was trying to slaughter him.

Rising to his feet, captured gun in hand, Agent “X” was for the moment master of that terrible room. The blazing, burning light in his eyes made the two unwounded men cower back. This human whirlwind was more than they could cope with. But they were small human cogs in the Octopus’s vast machine.

The sound amplifying extension into the board room had been turned on — the instrument that was supposed to carry “X’s” groans and pain-wrung words to the gloating ears of the directors. Instead it had carried the sounds of the amazing battle he had staged. But even as he fought, the Octopus’s ironic words seemed to ring in “X’s” ears. “I have certain small devices myself which could handle the situation…. A gas more deadly—”

Motioning the black-clothed men aside, Agent “X” crossed to the door of room 13. He flung it open, listened. He heard shouts, the thud of feet. Already reinforcements were coming.

He left room 13, headed straight toward the sounds of approaching men. He remembered the markings on another door he had seen. This was the door labeled No. 7 with the crimson words “danger” above and below the number. What danger the chamber held “X” did not know.

He flung down the corridor, almost to the elbow around which the others were coming. He checked himself before door No. 7, went through with a sidewise lunge, closed the door after him.

Expecting to find himself in another room like the torture chamber, he was fooled. A long dimly lit tunnel slanted down from this door. It was like a miniature subway. He plunged along, realizing that it was taking him to another part of the old factory block. It seemed to be the northwest corner.

Ahead was a door with glass in it and iron grille work. He pushed against it. It was locked. Behind him now he heard the sound of feet in the subwaylike passage, the hoarse shouts of men.

He reared up, looked through the iron grille, saw a lighted room. He got a confused impression of vats, bottles, metal tanks, jars. A man in a stained white apron was at work before a low table.

Agent “X” rapped on the door, and the man turned. He had aquiline features, a stringy beard, glasses. The Agent rapped again more impatiently, and the man gave an irritated shrug and strode toward the door. When he was close Agent “X” broke the glass of the door with the muzzle of the gun he had taken. He aimed the gun straight at the bearded man.

“Quick — open!” he hissed.

The man gave one gasp of terror, started to run, thought better of it. He came close, a lock clicked and the door swung open. Agent “X” pushed through.

“Who are you?” the man demanded.

Agent “X” clutched the man’s throat, and sent him reeling out into the corridor with a vicious shove. He closed the door, locked it, and turned back into this new room of mystery. One studied glance and he saw what it was.

Here was a completely stocked chemical laboratory. His eyes roved the shelves of bottles, jars and carboy containers. Here were deadly, explosive elements. Acids that would eat metal. Dies for counterfeiting purposes. Sinister poisons.

A huge safe stood against the wall, its door ajar. On a table were some record books — data to be used in this laboratory of the Octopus’s criminal corporation. The safe caught the Agent’s eye, held it.

HE leaped across to it, opened the door wider, then raised his head a moment and stared upward. Ventilators led toward the ceiling of this underground chamber. Motor-driven, fans were set in the ceiling to carry noxious gases away to some sort of airshaft above. A ladder snaked up to the fans to make oiling and repairs possible.

This ladder held “X’s” gaze an instant. His heart leaped. Then he saw that the metal ceiling and fans made an effectual barrier. There was not time to get through them — even supposing the airshaft offered a possible means of escape. Already the sounds of pursuit were plain. He could hear the shouting of men, the thud of swiftly running feet. The criminal “board,” frenzied at the Agent’s battle in room 13, were coming to hunt him down, reenforced with other employees of the place.

He turned from the ladder, flung open the only other door in the room. Another corridor showed; but signal lights were flashing along this. He saw dark figures racing toward him from its farthest end. He was trapped. Death was converging upon him from all sides.

He slammed the door shut, groped for a lock. There was none. And now the sound of feet was close to the grilled entrance through which he had come. This door was locked, but the glass in it was broken.

Even as he whirled the black snout of an automatic was shoved through. The Secret Agent flung himself aside as a gun spurted flame. The gun turned as a killer at the trigger tried to slaughter him.

“X” leaped to the wall of the room, pressed the light switch, plunging the place in darkness.

The gun in the killer’s hand continued to thunder. Bullets snapped and crackled around the laboratory. A glass jar broke with a jangle and a liquid of some sort gushed out. The Agent smelled the pungent odor of benzine. Then he heard a thud against the door. A battering device was being used. It was only a question of minutes before they broke in.

Eyes burning like coals in the darkness, Agent “X” stepped toward the shelf where the benzine had gushed from the bottle. He did a thing that seemed utter madness in that room of explosive chemicals. He struck a match, tossed it onto the shelf. Self-destruction to avoid torture seemed to be the Agent’s intention.

THE tiny flame of the match caught a benzine-soaked paper. A plume of flame whipped up. An exultant cry came from those behind the door. As the blinding flame of the benzine made wavering light in the room. Agent “X” stepped toward the big safe. Like a wraith he slipped into it, crouched back, holding the door.

Flame from the benzine licked upward. A bottle above popped. Something hissed like water from a hose. The contents of the bottle caught and a streak of livid flame shot up the full height of the shelf, a greedy, twisting snake of destruction.

As it reached the top of the shelf, a huge carboy of inflammable chemical burst open and sprayed the room with a drenching sheet of flame.

Agent “X” shut the safe door and crouched there in the darkness. A thundering explosion shook the room outside. He could feel the safe rock on its casters. It took him back to war days, this volleying and battering. Some one seemed to be striking the safe with a great hammer now.

It began to grow warm inside. Sweat trickled down the Agent’s face. In avoiding death in one form he had courted it in another. But the safe, with its thick steel walls offered the only protection anywhere in sight. His quick wits had saved him from the Octopus’s fury. And the men in the corridor outside would think he was being blown to pieces.

The thundering noises continued. The heat increased and the air became so stale and so infused with the reek of burning chemicals that it seemed no living thing could survive. The Agent soaked his handkerchief with a solution of ammonia salts which he carried in a small vial. He wrapped this around his nose and mouth, an improvised gas mask. But his lungs were beginning to ache with the bad air, his heart was laboring. An old wound in his side, a wound received long ago on a battlefield in France, ached, too. The scar of that wound was drawn into the outlines of a crude “X.” It seemed once again the symbol of the Secret Agent’s indomitable will. He was fighting a battle now, a battle against the smothering, reeking death that threatened to overwhelm him at any moment.

Chapter XIX

WHEN it seemed he could stand his steel prison no longer, the bombardment outside began to lessen. Even then he dared not open the door of the safe, fearing vapors of poisonous chemicals would rush in. The heat must have been terrific to make the safe as warm as it was. Only its fireproof qualities had saved him.

He waited seconds more, waited till it was a question of dying inside the safe or risking the air outside. Then he reached forward and pushed against the door.

Abruptly he was aware of new and terrible danger. The heat and the jarring explosions had made the door wedge. He brought his full weight against it. Still it would not move. It seemed almost as though the heat had welded it to the sides of the safe.

With blood pounding in his ears, with death coming closer every instant, Agent “X” began a new and fearful battle.

He thrust his feet against the back of the safe, pushed with all his might, struggling to keep his faculties from slipping into the black void which yawned. But only when unconsciousness was creeping over him did the door move a fraction of an inch. Another stupendous heave, bringing into play all the reserve strength of nerve and muscle — and the jammed door came free.

Blasting heat struck his face. But the air was relatively pure. The flames and explosions had consumed the chemicals in the room. Many of the poisons had counteracted each other.

The interior of the room was a complete wreck. The battering series of explosions from which the steel walls of the safe had saved him, had wrought havoc. He saw the sides and front of the safe were pitted.

Debris cluttered the floor at his feet. The unlocked door had been blown open. The glass in the other had let noxious fumes out, driven the killers back. But the steel and concrete walls of the room had withstood the shock of the explosions and had probably muffled the roar. The room was far underground. Agent “X” listened tensely for some human sound. There was none.

The shock of the explosions had gone upward. Agent “X” glanced toward the ceiling again. Then his pulses quickened. For three of the fans in the airshaft had blown out, forcing a rent in the sheet metal ceiling.

He stepped out into the room excitedly. The floor was so hot it scorched the soles of his feet. On all sides of him was heat, stench, ruin. But the iron ladder against the wall still showed in the eerie light of the smoldering chemicals.

The Agent leaped toward it, sidestepping a sticky, sooty mass that still bubbled and smoked. He grasped the ladder, drew his hand away. The metal was so hot it burned his flesh.

He tore his handkerchief in two, wet both halves with more of the ammonia solution, grasped the cloth in his palms. Heedless of the pain he ascended the ladder toward that rent in the ceiling.

With hammering pulses, the Agent reached its top, drew himself up through the rent to the crossbeams of the ceiling, stood a moment. It was suffocatingly hot here. The fumes of the chemicals, still smoldering below, blinded him, made him choke. He moved nearer the wall of the big air shaft, cupped a hand over his eyes. Then he clicked on a small flashlight.

There was no continuation of the ladder here. But a water pipe led up along the brick walls of the shaft. It was held fast by clamps set in the mortar. The Agent seized it determinedly. A man less agile, less certain of the interplay of nerve and muscle, could never have made that climb.

Several times he stopped when it seemed he could maintain his grip no longer. He clung desperately, knees braced against the rough brick wall, hands painfully singed, clutching the pipe. To let go now meant death, a sickening drop that would crash him on the beams of the laboratory ceiling far below.

He did not know what awaited him at the top of the pipe. But the coolness of the air increased. This shaft went right up through the heart of the factory building.

The Agent climbed on through age-long seconds. Somewhere, far below him, he heard sounds of human activity now. With muscles almost paralyzed from the long tension of holding and climbing, the weight of his body seemed to have increased many times.

Then, in the darkness, he saw a ghostly something. He clung with one hand, reached out. The lighter spot against the blackness of the smoky brick wall was a window. It gave into some attic room of the big factory. It was unlocked.

The Agent raised it, risking instant death as he clung with one throbbing hand. It took a painful effort to get the sash up. Then at last he thrust an arm across the sill, gripped the edges of it, clutched with the other.

In a moment his head and shoulders were through. He paused, elbows wedged in the narrow frame, then heaved himself over on to the floor inside.

FOR almost five minutes he lay in what amounted to a coma. During that time the splendid, dynamic forces of his body seemed to go through a process of rejuvenation. It was this ability of the Agent’s to take punishment that had brought him before through situations so fearful that it seemed flesh and blood could not endure them.

He rose to his feet at last. He was alone in this dusty loft. He crept back to the window, thrust his head out and listened.

Far down, through the rent in the metal ceiling of the laboratory, he could see the dim play of light. It might be the smoldering chemicals flaring up again. It might be the glow of a hand torch. He could not tell which. But there were no sounds of pursuit.

And why should there be? It was against all reason to suppose that anyone could have survived that holocaust in the laboratory. Rising clouds of soot and chemical fumes would obscure any tracks he might have made. The Octopus’s men would not suspect the escape.

A grim, hard light appeared in the Agent’s eyes. Somehow, he had to locate the place from which the Octopus had made his television broadcast. And he suddenly remembered an article among Van Camp’s possessions which had surprised him at the time. Now he suspected its significance. And he must get possession of it — ahead of the Octopus’s men.

Stealthily he began looking for a way down from his lofty hideout. He found a steel stairway leading to the next floor. There were elevators in the building; but these had long since been out of commission.

The Agent descended floor after floor, listening always for some sound. Ten floors above the street he took from his pocket a small instrument that looked like a folding, vest-pocket camera. It was the tiny, portable amplifying device which he had often used in his work with criminals.

He pressed the disc microphone on its black cord to the wall; put the body of the instrument, which was the earphone, to his head. He turned on the delicate rheostat controls.

But no sounds of foot vibrations reached him. Here was concrete proof that his escape to the top of the building had not been suspected.

The section of the factory building he was in came to the eighth floor level. The roof of another wing showed. The Agent went out on this, walked silently along under the stars till he came to the framework of a fire escape which led to the ground.

He stopped to get his bearings. There must be a secret alarm system on the high wall enclosing the factory on two sides. This he must avoid; and he must avoid, too, that side of the building where the shop of Colosimo Rici was located. Cautiously he descended to the factory yard at the fire escape’s bottom.

He approached the factory wall, looked up, paused. For seconds he marveled at the Octopus’s cunning. Before his understanding eyes was an alarm system no man would expect to find in such a place — the latest scientific protection device known to modern penology.

A series of three glass lenses was set in the factory building at the end of the wall. These lenses, hidden from the street outside by a projecting bit of boarding, focused along the wall at levels of one, two, and three feet.

THE barbed-wire on top of the wall was only a blind. A man might be careful not to touch it, thinking it was electrically charged. He might jump the wall, clearing it and the wire entirely — and still those hidden lenses would record on some dial below the fact of his presence.

For, to the Agent’s experienced eye, they were the lenses of the invisible infra-red, photo-electric alarm system, used in some of the most modern State penitentiaries.

Any opaque body, passing between those lenses and the photoelectric eye that received the rays at the opposite end of the wail, would instantly give warning.

Agent “X” made no attempt to climb over the wall. His one means of escape lay in the side of the building facing directly on the street. He moved around the junk-filled factory yard, locating at last an old spindle of insulated wire. He cut off fifty feet of this, rolled it up and climbed the fire escape to the second floor.

He opened a window on this floor on the side of the building directly over the street. He looped the wire through a radiator pipe inside, so that it hung double down the outside wall of the building. Then, hanging by the wire, he closed the window to within a few inches, and made the descent to the street.

The wire hung down still, but Agent “X” had both ends. He pulled on one, winding it in till the other snaked up, passed through the pipe and came down. He was out of the building now, with no clues left behind except that one window partially open. It was not noticeable from the street.

The darkness swallowed Agent “X” as he hurried away. He did not go to the drive-yourself car parked two blocks distant. Criminal eyes might be watching that. He chose the darkest, most unfrequented streets.

In a deeply shadowed spot between two buildings he stopped, reaching skilled, experienced fingers toward his face. The features of Van Camp disappeared under his touch. He stripped off the volatile substance and the transparent adhesive that had changed his features into a likeness of the criminal lawyer. He took the gray toupee from his head.

There was no time or opportunity for an elaborate disguise. But the Agent carried small tubes and vials of material with him. He used these to create one of his “stock” disguises.

When he emerged from the shadows he no longer resembled Van Camp. Ten years seemed to have fallen from his age. He walked quickly to a lighted boulevard and signaled a cruising taxi. This bore him to the hotel where Van Camp was registered.

The Agent bought himself a paper, strolled casually through the lobby, not glancing to left or right. A spy of the Octopus might be somewhere in the hotel.

His pulse beat increased as he took the elevator to the eighth floor. He had Van Camp’s key now. He folded his paper, walked resolutely along the hall. The instant the elevator door had closed, he entered suite 806 again.

VAN CAMP was still unconscious, exactly as “X” had left him. He was lying peacefully on the couch in the front room, as though asleep. But there was need for fast work. Any instant some sinister agent of the Octopus might arrive.

“X” slipped on a pair of gloves, went through the lawyer’s luggage again. He unstrapped the suitcase, brought out a small portable radio set. This was the thing that his photographic brain had recorded. This was what he had thought of instantly when he’d seen the image of the Octopus on the television screen, and heard the master criminal’s words come through the loudspeaker.

It seemed strange that Van Camp should bring a radio all the way to Chicago. Stranger still, considering that a radio instrument was already in the room, supplied by the hotel itself. It could mean only one thing. Van Camp expected to receive broadcasted signals from his chief. What sort of broadcast — and on what wave length?

The Agent examined tensely the brown radio box in his hands. At first glance it appeared to be an ordinary stock model midget set of cheap make.

But the back of it was sealed up. This was odd. Most radios of this type, he knew, had open backs to make the tubes and terminals easily accessible.

“X” turned one of the two dials which appeared to be wave-length and volume controls. He saw with a glow of excitement that this was a dummy front. The control snapped into some sort of socket with a click when he turned it. He turned the other to a corresponding position. Suddenly the whole front panel of the box came off in his hand. Behind it was another inset panel — and the Agent’s eyes snapped.

Here was a radio set such as he had never seen before. It was, in fact, two miniature sets, exactly alike, housed in the same cabinet; but with separate controls. One side of the panel was red Bakelite, the other blue. There were four control dials altogether; and, in the precise center of the panel, was a small loudspeaker with a screw head above it. This looked like the hand-setting screw of a clock. Then “X” bent forward with abrupt interest, noticing something else.

The front panel of the radio inside was scorched and cracked. There was an odor of burnt varnish and rubber. The whole cabinet was still warm, although Van Camp had been unconscious for nearly an hour! The Agent’s hands tensed. He thought quickly.

This mysterious fire inside the set explained itself. The strange radio bore an important relation to the activities of the criminal organization. And the Octopus, as soon as he had learned that “X” was impersonating Van Camp, had taken pains to destroy it. He had sent out some sort of radio impulse so powerful that it had short-circuited and burned up the mechanism of the set.

“X” snapped the false front back into place, tucked the set under his coat and started for the door. But he froze abruptly in his tracks. A faint sound had come from the doorway into the corridor. It was the metallic scraping of a skeleton key being inserted into the lock. It meant that one or more of the Octopus’s men had arrived to learn what had happened to Van Camp.

Chapter XX

AN emotion deeper than terror filled Agent “X.” Discovery now would mean the death blow to his plans, destroy the progress he had made. Knowing the Secret Agent still lived, the Octopus would change every sign and signal by which he controlled his organization.

“X” leaped to the window, stared down. It was an eight-story drop to the street. He looked along the face of the building, eyes narrowed calculatingly. A narrow ledge ran around the level of the floor he was on. It was a bare four inches wide. But it presented his only chance.

He looked at the radio set tucked under his arm. He couldn’t take that and maneuver the ledge, too. He must sacrifice it or be discovered. The Agent made an instantaneous decision. Another second and the door into the corridor would open.

He put the mysterious radio cabinet down quietly, slipped out of the open window. He stood upright in the cold night air, gripped the outside of the frame, then like a human fly, he crept along the face of the building.

Risking quick death by a plunge to the street, he flattened himself to the building’s side, moved crabwise along the narrow ledge. He passed two lighted windows. Guests of the hotel were unaware of the strange being who moved so close. He came to a fifth window that was open slightly. Was the room empty, or was its occupant asleep? “X” did not know. He must take a chance.

Clinging to his precarious hold, he raised the window softly and slipped into the room. In the dim light inside he saw the mound of a sleeper in a bed. But he cat-footed across the room to the door that led into the hall.

So softly that the sleeper did not stir, Agent “X” opened the door and went out. The corridor was deserted. The man with the skeleton key must have passed into Van Camp’s suite. By a few seconds only Agent “X” had escaped detection. And he dared not go back for the radio set now.

He descended into the lobby, strolled into the night streets….

TWO nights later Secret Agent “X” sat in absorbed concentration before a table in his Chicago hideout. Forty-eight hours of intensive activity lay behind him.

The living room of his hideout had become a mad jumble of apparatus and equipment. He had made purchases from more than a dozen leading radio supply stores in Chicago. He had torn apart, built up, tested a score of complex receiving sets.

There were coils of wire, sheets of metal, dozens of tubes, dozens of condensers scattered about the floor of the apartment. Glue pots and soldering irons added to the confusion. Scraps of foil lay on the floor as though a silver snowstorm had fallen. Every available spot where anything might be set was covered. But in all this clutter and confusion, Agent “X” worked with grim, unswerving persistence.

Before him on the table now was a superheterodyne set which he himself had assembled. This set covered wave lengths from twelve to five hundred and sixty meters. At almost any intensity the audio amplifier gave undistorted output. Trimmer condensers and other balancing devices had been abolished. Static interference had been reduced to a minimum by a low-pass filter circuit of unique design.

Secret Agent “X” had demonstrated his mastery of a branch of science which is a life career for many men. For, with its other qualities, this all-wave set possessed amazing sensitivity.

Broadcasts from many parts of the world had come in on it. Calls from London, Paris, Berlin, New York, Los Angeles, Detroit — all the great cities of Europe and America. Police calls had come, too. Calls from ships, planes, and from hundreds of private stations.

For nearly twelve hours at a stretch Agent “X” had remained in that room, listening. There was hardly a station in the United States, Canada or Mexico, private or commercial, that he had not tuned in on for a moment at least as he sought patiently for some broadcast that might fit in with the clue of Van Camp’s strange set.

And now, suddenly, a mysterious message was coming in out of the night. The Secret Agent’s eyes were glowing with the light of rapt intensity. On a wave length lower than that of any other call he had received so far, a strange jumble of words was being repeated at fifteen-minute intervals.

“Tee — ten — sent — to — ner — del — that — ree — dows — un — tues — night — oh —”

Those jerky syllables were in a man’s voice — a voice that Agent “X” could never mistake. It was the precise, obviously disguised voice of the Octopus.

But what was the master criminal saying? There was a maddening, unfathomable riddle in those spaced syllables. “Sent — to” and “tues — night” were the only ones that appeared to make any sense. Something had happened, or was going to happen Tuesday night; but what? Every second syllable vanished, and these gaps of silence formed an amazing puzzle.

Three times the Agent listened to the strange message, then leaped to another instrument standing on a chair near by. This was a complex directional aerial attached to the radio. Copper wire was coiled in the flattest possible plane, mounted on a rotating central post. A micrometer screw controlled the movements of this coil.

Feverishly “X” turned this screw until the message, coming in a fourth time, grew louder. A gold-foil galvanometer at the base of the aerial showed at last that maximum volume had been attained. Any slight movement beyond that point made the message dim. A small radio beam compass also worked in conjunction with the aerial. The Agent studied this tensely. The clocklike face of the compass turned as the aerial was rotated, but the needle remained stationary. From the relation of the two, the Agent got exact bearings. The red compass line, corresponding to the plane of the aerial, showed almost due east.

“X” suddenly rose. He packed up his radio set and other instruments with speed and care. In quick strides he left his hideout. The night air felt good after the prisonlike life he had been living for twelve hours. He deposited his equipment in the seat of his car, drove like a demon in a southerly direction away from Chicago. There was no telling how long the Octopus’s message would continue to be broadcast.

FOR a half hour “X” raced through the night, thundering over night-darkened country roads. Twenty-five miles south of Chicago he turned off into a narrow side lane and parked in a grove of trees. Here he set up his instruments again and bent over them intently.

Five minutes, and that mysterious call was once more being repeated.

“Tee — ten — sent — to — ner — del — that — ree — dows — un — tues — night — oh —”

A second time the Agent adjusted his radio beam compass and directional aerial until the supersensitive leaves of the special galvanometer showed maximum intensity. Now the red line on the clocklike face of the compass was pointing a tiny fraction north of due east. It was no more than a single degree on the compass’s graduated face. Agent “X” set a screw-head which locked the line where it was.

He opened a detailed scale map of the United States put out by the Geodetic Survey. It did not vary from actual distance by more than a tenth of a mile at most.

“X” marked the two positions from which he had taken the directions, marked the compass points in fractions of degrees. Like an astronomer photographing a star from two different points, he now had a paralax.

Careful mathematical estimates of the sides of this elongated isosceles triangle would enable him to determine where they converged. This would be the spot from which the mysterious broadcast had been made.

Back in his hideout Agent “X” covered a sheet of paper with exact geometrical symbols and figures. With a ruler marked off in millimeters and a pair of the finest calipers he went over the Geodetic Survey map.

When he straightened at last, his eyes were snapping pools of light. The broadcast of the Octopus was coming from a county in western New York State. The Agent had the precise spot marked off on his map. The station was somewhere in a circle, not more than a half mile in diameter. The data collected by means of his precise scientific instruments could not lie.

The Agent changed to his disguise of Martin, the newspaper man, again. He got in touch with Hobart at once, arranged to have the ex-dick meet him at the Chicago airport within half an hour.

“X” beat the detective to the airport, chartered a fast plane and a skilled pilot from a commercial flying company. In this he and Hobart flew to Buffalo.

THE Agent had a hideout in Buffalo, too, also a car garaged under another name. He kept Hobart waiting while he got this car. Then, with Hobart beside him on the seat and his elaborate scientific equipment packed in the rear, he headed off into the country.

Twice Agent “X” consulted his road map. A State highway led him close to his objective. He swung into a country road, the ruts of which made the big car jounce like a ship on a stormy sea. But in spite of the bad condition of the road and its many curves, Agent “X” switched off the car’s lights.

Guided only by the dim light of the stars he drove ahead, eyes seeming able to pierce the darkness. Jim Hobart swore as a particularly bad rut made the car leap and clatter.

“That crack-up in that plane of yours had nothing on this, boss! I’ll be needing an air cushion to sit on for the next week.”

Agent “X” gave a low command for quiet; then whispered to Hobart to keep his automatic handy. He stopped, flicked on the dim instrument board light a moment, and consulted both his road map and the Geodetic map again.

He switched off the light, listened, but nothing sounded except the moaning of the night wind through the trees of the rocky, wooded country. Agent “X” spoke guardedly.

“I want you to stay here, Jim, and keep watch of the car while I scout around. Don’t move till I get back.”

“X” slipped like a wraith into the darkness, walking surefootedly. Black as the night was, things to him were visible. He had trained himself long ago to see under circumstances in which other men could not.

Cautiously he walked through the sparse woods. Any moment he expected to come upon some old barn or house which held sinister secrets. Perhaps within the next hour he would come to grips with the Octopus, the man who mysteriously controlled a crime corporation covering the whole United States.

A half hour passed and Agent “X” saw nothing but trees, ground and rocks. Systematically he searched that circle he had marked out on his map. With the thoroughness of a hound, never lapping over back tracks, he went over the circle, crossing its diameter first, going over one half, then the other.

At last after two hours he stopped, eyes bright, jaws grim. Failure had marked his course tonight; failure after all those precise recordings and careful computations.

There was no single sign of human life within this circle out of which the broadcast had come. There was no hidden station, no barn, house, shack, cave or suspicious point. It was only what it appeared to be — empty, desolate country. Once again the Octopus had checkmated him.

Chapter XXI

DISCONSOLATELY Agent “X” went back to the car where Hobart was waiting. “X’s” shoulders drooped for the first time since he had begun his quest for the master of crime — the Octopus. Out of the darkness Hobart’s hushed voice reached him.

“That you, boss?”

“Yes.”

“Any luck?”

“No, Jim.”

Hobart cleared his throat, asked a hesitant question.

“What was you after, boss?”

“A big shot, Jim — a crook who makes all other crooks in the country look like small fish.”

“Gees! And you thought he was hanging out in this dump?”

“Yes, I did. Figures told me so — and figures don’t lie!”

Agent “X” gave no explanation of this seemingly cryptic statement. He lapsed into grim-lipped silence.

Hobart and “X” stayed the rest of the night in a small commercial hotel in a little town outside Buffalo. They registered again as traveling salesmen.

When morning came Agent “X” drove out alone to the circle he had marked on the map. He convinced himself that his night-time search had been right. There was no hidden broadcasting station here.

When he returned to his hotel room, Hobart held out a morning paper excitedly.

“Look, boss — here’s the dumbest kidnap racket I’ve ever heard of a crook pulling. A guy has warned a millionaire that he’ll grab the millionaire’s kid if the millionaire don’t cough up two hundred grand in advance. Tie that if you can — a crook asking advance payment for a job he ain’t done yet! Fat chance he’s got to get it, with the federal government clamping the lid down on kidnapers. He ought to have grabbed the kid first and asked for his dough afterwards, like the rest of ’em. Even the crooks are getting sappy these days.”

Agent “X” took the paper with no comment. The news item bore the address of a small mid-Western community. It said:

Agent “X” stared at the paper. The light in his eyes became so intense that Hobart, watching him, gave a hoarse exclamation.

“What is it, boss? That guy Mandel ain’t a friend of yours, is he?”

“No — not a friend.”

“But you know something about him.”

“I think I do!”

Silently Agent “X” took a piece of paper from an inner pocket. On it was printed the strange message he had received on his special radio the evening before.

“Tee — ten — sent — to — ner — del — that — ree — dows — un — tues — night — oh—”

Before the fifth and sixth syllables respectively, he inserted two others, “War” and “Man” and put the word “note” between “sent” and “to.” Sent note to Warner Mandel.

Agent “X” got up, paced the room excitedly. Here was conclusive evidence to him that the Octopus was the man who had threatened the millionaire brewer. And if the Octopus was behind the proposed kidnaping there was a likelihood, almost a certainty, that it would be carried out, despite the heavily armed police cordon. He turned to Hobart.

“There’s nothing phoney about this stunt, Jim. One of the cleverest crooks in the U. S. is behind it — the man I’ve been looking for.”

Jim Hobart shrugged. “I wouldn’t worry, boss. There’s been a lot of kidnapings lately. The cops are on their toes. With them on the look-out for the next twenty-four hours no crook will have a chance of getting inside the Mandel place.”

A grim smile twitched the Secret Agent’s lips. Hobart didn’t know as he did that the Octopus was a man of satanic genius and unexpected originality. Neither did the police. And yet he couldn’t warn them. Publicity would be given such a warning — publicity that would reach the ears of the Octopus, and let him know Agent “X” still lived.

“X” made a quick decision. “Pack up your duds, Jim. It’s time we got started.”

“Where to now, boss?”

“Out to the place where this kidnap stunt is going to be pulled.”

WHEN they reached the city where Warner Mandel lived, Jim Hobart was again disappointed at the inactive role his employer, Martin, gave him.

“Just hang around the hotel, Jim,” said the Secret Agent. “Your name this time is Bill Conrad. I’ll call you if I need you. Keep your ears and eyes open.”

“X” got himself a small furnished room in another part of the city. For more than an hour he combed the ether with his all-wave radio. No further messages flashed out of the sky.

As the afternoon deepened and the shadows of evening came, they seemed to portend evil. Tonight at midnight the forty-eight-hour limit would be up. The shadow of the Octopus would fall in sinister fashion over Warner Mandel’s son.

Agent “X” drove by the big Mandel estate. It was on the outskirts of the city. He saw that the newspaper report was right. Mandel’s big place had been turned into a fortress.

It covered a whole city block. At each corner, though it was still daylight and the period stipulated by the kidnapers had not elapsed, a radio patrol car was stationed. Every hundred feet along the fence that skirted the place a guard with a rifle stood. Plain-clothes detectives and federal men were sauntering about the lawn.

The Mandel child was nowhere in sight. Hidden behind the walls of the house, with other plain-clothes men inside, it seemed fantastic to suppose that any criminal could get to him. But Agent “X” wasn’t at ease.

“X” saw a tradesman on his way to the kitchen entrance stopped. He was cross-questioned by the police. His delivery auto was searched before he was allowed to enter. An armed detective got up on the seat with him. This spoke well for Commissioner Davenport’s thoroughness. But the silent closing down of the evening shadows seemed as ominous to “X” as the slow, purposeful curling up of an Octopus’s tentacles.

He drove by again after dark, saw that the guards had been doubled and that searchlights had been set along the fence. Their bright beams illuminated all four streets in both directions. When “X” tried to enter one of these streets, he was stopped, questioned, and told to detour through another block.

The Secret Agent’s eyes were bright. He must get inside that cordon of police. To be at hand if the Octopus dared to strike, he stood ready to risk exposure or death at the hands of the police. But there was only one way to achieve his end. He must make a desperate play as he had done before in his strange warfare on crime.

Throughout the afternoon he had Jim Hobart make discreet inquiries concerning the city’s police. Four deputy inspectors had been assigned to the Mandel case. Two for day detail. Two others for night. Hobart got the names and addresses of these men from the city’s newspaper office. One, assigned to night duty, was a bachelor living alone in a small apartment. This one was Deputy Inspector Thomas Dulany.

A HALF hour before Deputy Inspector Dulany was scheduled to start for his post of duty that night he received a visitor. A tall man with a pleasant face and alert eyes rang his bell. The man handed the inspector a card bearing the name of Dillon. It stated that he was from the State’s superintendent of insurance.

“I’d like a few words with you on this Mandel matter,” said the man called Dillon. “There are some insurance hazards involved. In case anything should happen, the superintendent’s office must be prepared to render decisions.”

Inspector Dulany looked at his watch, motioned to the front room of his apartment. He was a ruddy-faced, competent looking man who bore the mark of good living on his even features.

“Haven’t much time,” he said. “I can give you just fifteen minutes, Dillon.”

“Splendid,” said the other. “That will be ample for my business with you.”

He walked behind Dulany into the drawing room of the small apartment, made sure there was no other occupant and that the shades were drawn. Inspector Dulany motioned to an overstuffed chair, took one himself opposite.

“Now, Dillon, what is it you want to know?”

The visitor fumbled a moment in his coat pocket.

“Let’s see — I have a questionnaire here,” he said.

His hand came out more quickly than it went in, so quickly that Deputy Inspector Dulany had only a bare moment to see that the fingers contained not papers, but a gun.

Before he could open his mouth or leap out of his chair, there was a faint hiss. Vapor from the muzzle of the gun shot into his face. It was harmless vapor, but Dulany gave one convulsive movement and slumped back into his seat. He looked like a man taking a peaceful after-dinner snooze.

The man who called himself Dillon went instantly to work. There was little time for what he had to do. Much depended on it. Certainly his own life and safety. But he wasn’t thinking of those. He was thinking of the Octopus, and of the amazing, daring threat that had been made.

His disguise of Dillon came off, revealing the strange, changeable countenance of Secret Agent “X,” that countenance which in some lights seemed youthful, almost boyish, in others strongly mature.

The Secret Agent brought Dulany’s shaving mirror from the bathroom, set it up on the drawing room table. He took his portable tubes of plastic material from his pocket. He brought out other tubes of pigment. One of these matched Dulany’s coloring. Agent “X” began to transform his own face.

At the end of ten minutes he had achieved again one of his remarkable disguises, a disguise displaying the talent which had placed him at the head of impersonators throughout the world. Two Deputy Inspector Dulanys seemed to be in that room.

Agent “X” lifted the real inspector as though he were as light as a child, carried him into his bedroom and stretched him comfortably on the bed. He then took the police officer’s credentials. After this he gave Dulany a harmless hypo injection which would insure his staying unconscious for the remainder of the night.

In Dulany’s car, looking like Dulany and with Dulany’s credentials, Agent “X” went to Warner Mandel’s estate. Two city detectives recognized Dulany at once. “X” was admitted without comment.

As a credited police official he was free to go where he wished over the Mandel estate, inside and out. He took note of the servants carefully, learned that they had all been with the Mandels three years or more. The precautions to guard the Mandel boy were even more impressive viewed from the inside.

Agent “X” didn’t want to draw attention to himself. He was guarded in his speech, watching Deputy Inspector Grogan, who was his colleague. When he saw that Grogan refrained from intruding himself on the family, he did likewise. He caught a glimpse of Warner Mandel, however, a big man, who seemed cheerful and confident.

THE early hours of the evening moved by uneventfully. Agent “X” chatted with Grogan, learned that in the opinion of the cops all these elaborate precautions were something of a joke. They were attributed to the fear hysteria which a wave of kidnapings in the U. S. had caused. “X” could not tell this man or others of the dread cunning of the Octopus.

But, as midnight came, his sense of uneasiness deepened; his sense that some climax would be reached soon. A light summer drizzle fell on the lawn and shrubbery. The sky overhead was pitch black. But the searchlights on the four sides of the Mandel estate cut brilliant swathes of radiance through the darkness.

Agent “X” strolled along the fences, seeing that the armed guards were vigilant. No one outside the police had entered the Mandel place. But suddenly from the upper floor of the big house came a piping, childish scream.

It was unexpected, abrupt as the sudden crack of a gun in the night. That scream electrified the army of police and federal operatives into action. It tingled through the blood of Agent “X”; made him exclaim harshly, and tore toward the house at a run.

The scream was repeated; then it seemed to be choked off. A detective flashed his torch toward the roof. Lights appeared in many windows. The detective who had flashed the torch gave a shout of sheer amazement. He pointed wildly, stumbled, almost fell.

Agent “X” was near enough to see what had excited him. A black something was hurtling down off the roof of the house. It did not reach the ground. It dropped ten feet, swooped through the air, skimming high over the heads of the staring police.

Agent “X” caught a glimpse of the small, frightened face of a child. He heard again that piping scream; saw another face in that black thing above. There were no wings on the thing, no propeller. It was like the glistening black body of a wheel-less racing car. It made no sound except a faint sigh as it swept through the air.

The police held their fire, fearing they would hit the child. But suddenly, out of the front of the black car overhead, a flickering point of light came and went. A series of pops sounded.

Around “X” men staggered and fell, cursing, groaning. Crimson masked horribly the white face of a detective near by. The man threw up his hands, fell to the lawn, shot dead where he stood. The black, deathly car, with the kidnaped child in it, soared up over the tree tops and disappeared in the night sky. The horrible realization clutched “X” that the Octopus had made good his threat.

Chapter XXII

HE was utterly stunned for a second, as dumfounded as the police around him. The Octopus had accomplished the seemingly impossible, snatched the Mandel child from under the very nose of the law.

Agent “X” did not speak to the men about him. His eyes were glowing with deep emotion. His thoughts were racing. The sight of that black car stirred old memories. A theory was already coming to life in his mind. But the excitement around him precluded thought at the moment.

Men were shouting orders. The wounded were groaning horribly. The siren of a police car rose into a frenzied wail. The car shot away in the direction that the sailing thing had taken. From the house came the sudden scream of an hysterical woman. Agent “X” turned and ran across the lawn.

A cop inside the house was frenziedly calling an ambulance. Deputy Inspector Grogan was on hand. “X” followed him up a flight of stairs to the second story of the house. Somewhere ahead the screams of the woman sounded. A big man went lunging down a hall: Warner Mandel.

The woman was in a small blue decorated bedroom at the end of the hall. A tiny rumpled bed stood by a window. Small bed things were disarranged.

The Agent felt a tug at his heart, felt compassion for this woman, the mother of the kidnaped child. The fiend whose tentacles reached over the whole country had brought sorrow to another home.

“Harold! My baby!” shrieked the woman. The big man tried to comfort her. Detectives and federal men were milling about. A door showed at the side of the bedroom, opening into the child’s nursery. Agent “X” entered this room and saw that a window was raised. This in turn gave onto a flat, open sun roof. A white-faced maid was talking excitedly to a detective.

“It was here, sir, I first heard him cry out,” she said. “Some one must have carried him through that window.”

Agent “X” went out on the sun roof, now dark. Grogan followed him. The roof was forty feet square, flat. A low railing ran around it. Agent “X” went to this. At one side the paint of the railing was scraped. It was from here that the uncanny black car had plunged, down and over the trees into the night sky with its pitiful, innocent burden.

Agent “X” turned back into the house, stopped suddenly.

An abrupt sound had stilled the crying of Mrs. Mandel, stilled the hoarse, excited chatter of the detectives. It was the sound of a series of crashing, frenzied blows.

“Good God — what’s that?” Warner Mandel’s voice boomed out above this new noise.

The sound seemed to come from the servants’ wing. “X” started down the corridor at a run. Deputy Inspector Grogan and two detectives behind him. The crashing continued, as though a mad man were swinging a club.

A white-faced maid popped out of a door at “X’s” right, wringing her hands. “It’s Mr. Seymour’s door, sir. It’s him making that noise, sir.”

“Mr. Seymour?”

“Yes — poor Harold’s tutor, sir. There must be something terrible happening to him.”

Agent “X” leaped to the door of the tutor’s room, reached for the knob, struck a thundering blow with his fist.

“Open — quick!” he shouted.

But the door was locked. The detectives came up, added their fists to the din.

The crashing noises inside the room ceased abruptly. But no footsteps approached to open it. Agent “X” stepped back, shoulders hunched like a football player about to tackle, ready to crash through. Then he stopped as if frozen.

Another sound came through the door now. It was a single staccato crack, the report of a gun. It was followed by the ghastly thud of a falling body.

Head down, arms stiff, Agent “X” plunged against the door. The panels cracked, a piece of woodwork gave way. The door burst open. The detectives were at his heels, and they started in amazement. A man lay on the floor, a gun fallen from his fingers, a pool of blood at his head.

“It’s Mr. Seymour!” shrieked the terrified maid. “He’s killed himself!”

THAT the man was a suicide was obvious. But Agent “X” hardly looked at him in that first instant. He was staring at the side of the room, looking at a heavy chair that was splintered and broken.

The top of a heavy table was smashed, too, and something lay on it. This was the splintered cabinet, the broken tubes, the scattered fragments, of a small radio set. Seymour, the tutor, had smashed the set as though in a frenzy. Then he had blown his brains out.

With a stifled exclamation Agent “X” bent over these broken pieces. He saw the blue and red coloring of two separate dial panels; saw that there had been double sets of controls. Here was a radio set similar to the one Van Camp had owned.

He picked something out of the splintered fragments. It was a small clockwork mechanism which could be wound with a key. This he quietly slipped into his pocket.

The implication of the thing was plain. Seymour had been in the pay of the Octopus. The mysterious message had been sent to him. Now, in a fit of remorse, or in rebellion against an evil force that he had submitted to, he had killed himself.

Deputy Inspector Grogan was swearing fiercely. “The kidnaping was too much for this poor guy. He went nuts — put a bullet through his head.”

“X” said nothing to enlighten Grogan. Let the police put whatever significance they chose on this occurrence. His own conclusions were already formed.

The night was almost over when Agent “X” finally left. His heart was heavy for the Mandels who must suffer hours, perhaps days of anxiety. But his own mind was filled with grim resolve. The small clockwork mechanism in his pocket, coupled with what he already knew concerning the Octopus’s broadcasts, might lead him along the right trail.

The Octopus had mentioned two projects on that night of the board meeting. One had already been carried out. What was the other?

Agent “X” went back to Deputy Inspector Dulany’a house. He felt called upon to take steps to see that Dulany did not talk for a week at least. If the man made report of the mysterious Dillon — as he surely would — news of Dillon’s visit would reach the ears of the Octopus. He would instantly surmise that Secret Agent “X” was still alive.

Reluctantly the Secret Agent took out his hypo needle again and put into the barrel of it a small, colorless liquid. The Agent, a master of pharmacology, had synthesized this liquid himself from a peculiar blend of narcotics. It had power to create temporary amnesia, or loss of memory, from one to two weeks. After that the patient recovered all his mental powers. It wouldn’t hurt Dulany. It would only perplex and embarrass him. Until he regained his memory his friends on the force would merely think the excitement of the Mandel kidnaping had deranged him.

The Agent gave the deputy inspector the full dose of the drug; then quickly changed his disguise and left by the fire escape.

Hours of research followed. Hours in which “X” bent over Seymour’s clockwork mechanism, tore it apart wheel by wheel and screw by screw, reassembled it and studied its purpose. At the end of that time Agent “X” raised his head, satisfied. He now understood the secret of the Octopus’s strange broadcasts.

These broadcasts were sent out on two different wave lengths, alternating every other syllable. The sentences were chopped in two to anyone listening in. They were practically incomprehensible. The fact that certain words happened to fall on certain syllables only made them more mystifying.

The clockwork mechanism of Seymour’s had been a device which automatically changed the wave length every other syllable. It connected the loudspeaker first with one radio set, then with the other, so that a clear, uninterrupted message came out. The path which “X” had to follow was now plain. He must learn the nature of the Octopus’s next “project.”

IT was four days later that the Secret Agent’s energy and patience were rewarded. Back in his Chicago hideout he had kept constant vigil.

On the table before him stood two of the powerful all-wave superheterodyne sets now. The tubes, dials, and controls of both sets were identical. An automatic, clockwork wave-alternator, such as the one Seymour had possessed, connected them. This the Agent had himself constructed.

Hour after hour he had waited before his sets, keeping them switched on with the dials set for short wave lengths. Sometimes he had snatched winks of sleep. Sometimes he had eaten a scant meal in the hide-out But ceaselessly he had kept close to the radio sets with infinite, inexhaustible patience.

And now one of the mysterious interrupted messages in the Octopus’s voice was coming in. The Agent, tense and bright eyed, bent over his dials.

“Tee — ee — en — s — en — a — red — off — brose — watch — for — nal — will — low —”

The jerky, spaced syllables came out of the loudspeaker. The Agent found that the massage was being repeated every ten minutes. He switched the first set off, turned on the other. Combed the ether eagerly till another strange message came in.

“Eight — four — lev — s — mor — ci — be — ee — am — light — sky — sig — hook — be — ered —”

He started his clockwork mechanism, threw in both radio sets and waited ten minutes. Then, while the Agent listened spellbound, the syllables on both wave lengths came in as the clockwork mechanism alternated the sets. The mystery was at last solved.

“Eight-y-four e-lev-en S S Mor-en-ci-a. Be read-y off Am-brose light. Watch sky for sig-nal. Hook will be low-ered.”

Here in this short message the second “project” of the Octopus was revealed. The Agent listened while the message was repeated. It told plainly that the Octopus had a man designated as 84–11 on the Steam Ship Morencia. Told that a mysterious signal was to flash from the sky when the ship arrived off Ambrose light, that a hook was to be lowered.

The Agent switched on his directional aerial and radio-beam compass. These showed, an entirely different location for the broadcast now. No need even to speed from Chicago to obtain a paralax. The message must be coming from a powerful, short-wave station located on some type of aircraft. By the time he reached the spot his instruments designated, the craft would be miles away.

But, in a frenzy of activity, the Secret Agent began packing up his equipment. In less than an hour he was bound by fast plane for New York City.

Chapter XXIII

JUST at sundown the next evening an autogyro took off from an air field on Long Island. A rich young sportsman, who gave his name as Musgrave, had arrived at the field that morning and bought it. He had paid spot cash. A bill of sale and a Department of Commerce license had been rushed through.

Musgrave stated that he was flying down to his home in the South. He appeared to have a flare for mechanics. All afternoon he had worked over the gyro inside a hangar. At the last he tossed some bulky luggage into the forward pit.

The craft climbed like a wide-winged moth into the orange and red sky. It mounted steadily, till it was no more than a black dot over New York. Then it disappeared behind a cloud.

No one guessed that Musgrave was not the pilot’s real name or that his inconspicuous features formed another brilliant disguise of Secret Agent “X.”

A few brief inquiries in New York made by Jim Hobart had brought to light facts about the steamship Morencia. She was scheduled to arrive at quarantine about midnight. She carried on board five million dollars in gold from the Bank of France, part payment of an inter-Allied debt to America.

The news of this golden cargo explained the Octopus’s interest in the ship. It explained the reason for one of the Octopus’s paid representatives, No. 84–11, being on board. That a spectacular, daring raid on the ship was planned was certain in “X’s” mind. That it would take place in the air was also a foregone conclusion.

He had paid off the faithful Hobart after his investigating work was done. From now on “X” knew that he must work alone. Hobart was unaware of the sinister forces that existed. “X” could not take the young man completely into his confidence; for to do so would be to reveal his own identity. And he refused to bring Hobart under the shadow of unseen death as he had McCarthy. He must go up against the Octopus single-handed. But Jim Hobart had proven his courage, loyalty and dependability. The Secret Agent, if he lived through the battle before him, planned to use the ex-dick in other great manhunts.

Light of the setting sun fell on the autogyro’s wind vanes. It had risen high above a piled bank of cumulus clouds. It seemed to float along in a world devoid of any living thing.

The Agent reached forward, pulled a wire attached to a device which he himself had installed. The thunder of the engine was reduced to no more than a hollow rumble as a special, triple-expansion muffler deadened its explosions. More moth-like than ever now seemed the strange sky craft. It was a ghost moth far above the world, its wings touched with the orange flame of the sunset.

Twenty-five miles down the coast Agent “X” descended to a lonely field. The gyro floated down out of the sky with the silence of a wraith. It dropped out of the clouds, descended with the whirling vanes into the small field which was sheltered by barriers of high trees. There it rolled to a stop.

Under cover of the fast-falling darkness Agent “X” got out his radio set again. He wasn’t expecting a message from the Octopus. Twenty minutes of experimental tuning and he had picked what he wanted out of the ether. This was a ship-to-shore telephone conversation from the Morencia.

A placid American business man was telling his wife that the ship was on time. He was saying good night to his children, telling what a gay time he had had on the Continent, promising a more detailed account when he reached shore.

The Agent smiled grimly. This good husband and father didn’t know that the ship carried a passenger who was in the pay of a dread criminal corporation. He had no inkling of the exciting events that were to take place before the Morencia reached port.

Listening in on a code radio message, Agent “X” verified the fact that the ship was running close to schedule. By ten thirty she should be somewhere off Ambrose channel.

UNTIL night shrouded the coast, Agent “X” waited beside his gyro. Then he started the motor again, took off out of the small field. The gyro sailed off up over the tops of the trees, climbed into the black sky. Muffled, it slipped through the darkness with a steady swish of the great wind vanes, like some huge night-flying bird.

Agent “X” headed out over the open sea. The lights of the New Jersey coast were far below him. Still he climbed. Three thousand, four thousand, five thousand feet showed on the altimeter. He was up above the clouds now, up where the wind blew a cool, steady gale. The craft was so stable that she could practically fly herself alone.

“X” reached into the forward pit, drew an object like an old-fashioned talking machine horn from a box. There was a set of ear-phones attached to it by a black, flexible wire; also a powerful battery. He clamped the earphones to his head; cut the gyro’s motor and let the craft glide downward. Now the sighing of the gale in the vanes was the only sound.

The Agent listened tensely. The horn in his hand was another type of sound amplifier. It was a modification of the “electric ears” used to detect aircraft during the World War. Such instruments had warned Paris and London of approaching air raids.

No sound came except the mournful hoot of a steamer far out at sea. Faint starlight fell upon the clouds below “X.” The gyro was gliding down into them.

Twenty minutes passed and the white arms of the ghostly mist flashed by the descending craft. It burst through the clouds at last. “X” had glided two thousand feet lower, and still no sound of another motor in the sky.

Once again he started his own engine and mounted till he was far above the clouds. Seven thousand feet this time, and he cut his engine dead again. The silence of the night was like an oppressive, brooding presence. Agent “X” was in a lonely world of cloud, and air and infinite space.

Then abruptly he leaned sidewise over the coaming of the gyro’s pit. The muscles of his face grew rigid. His eyes narrowed and he made a grab for the slack controls.

He had heard no sound — but directly below him, not fifteen hundred feet distant, a great black monster was rising up out of the mist. Clouds broke from the monster’s back as white foam might break from the back of a whale.

The outlines became clearer now. The thing was a huge blimp. She was not only rising. She was moving ahead under the thrust of her propellers. And, in that instant, the Agent realized that the blimp’s motors were muffled so perfectly that not even his sensitive amplifier could detect the throb of their exhausts.

He snatched the phones from his head, started his own muffled engine. Gently he pulled the gyro’s elevators up, climbed slowly, traveling above that great shape below. His pulses were hammering. The light in his eyes had become like that of a questing eagle. His patience, the infinite pains he had taken during the past week were at last rewarded. Below him, there in the night-darkened sky, with the dim white sea of clouds as a background, was the sinister moving hideout of the Octopus.

The Agent looked at his watch under a tiny light on the gyro’s instrument panel. Ten fifteen.

The blimp below was moving steadily out to sea. The off-shore gale increased. The clouds below began to thin. Far ahead on the horizon Agent “X” caught a glimpse of the lighted portholes of a ship.

The blimp began to descend now. It dropped slowly two thousand feet, passed through the thin veil of clouds. Straight toward the ship it went. Agent “X” waited. Sometimes he lost sight of the craft below. But for a few seconds only. Then his sharp eyes caught again that nosing black shape. To catch the Octopus red-handed was his plan tonight.

The clouds had disappeared entirely now. The ship on the black surface of the sea below had grown larger. Ten minutes more and it was directly underneath.

The blimp made a wide circle. Its silent motors drove it ahead at three times the speed of the Morencia. It came up behind the boat, nosed directly over it. The speed of the blimp decreased until it was flying at the same rate as the boat. Agent “X” cut his gyro motor until its idling speed just kept the craft level.

The wisdom of his move in using a gyro was now evident. In an ordinary plane he would have had to circle, run the risk of being seen from those on board the blimp. The helium-filled bag of the blimp prevented him from seeing the signal lights that must have flashed.

For a brief instant, through powerful binoculars, he saw a pinpoint signal light on the deck of the Morencia. The watcher below must have had glasses trained on the night sky. The Octopus would never have run the risk of signals that casual eyes of ship’s officers might see.

IN the next fifteen minutes the blimp rode evenly above the harbor-bound steamer. What took place during those fifteen minutes Agent “X” could not see. But he knew that a daring, well-rehearsed robbery was in progress. He guessed that five million in gold was leaving the sea craft below and being hoisted to the aircraft above.

For suddenly the blimp increased its speed, began to rise, and the Agent tilted the vanes of his gyro up also. The robber was leaving the scene of his robbery with his spoils. Once Agent “X” looked back, and saw that brilliant lights had flashed up on the deck of the Morencia.

Searchlights from the ship’s pilot house began to comb the sea frantically. The steamer veered away from its course, wallowed in the Atlantic swells. The theft of the gold had evidently been discovered. Whoever 84–11 was, he had done his part well. But “X” knew he was only a minor cog in that vast machine of crime which the Octopus headed.

He continued to follow the blimp, mile after mile toward shore. To trace it to its secret hangar was his purpose. To take the Octopus and the stolen gold together. But suddenly the Agent’s eyes narrowed. Looking ahead now he could not see the twinkling lights of shore which should have been there. Something vast and gray loomed up. High above the gray mass a whitish rim of starlight was visible. “X” knew what that gray mass was. Fog.

His heart sank. The blimp wasn’t rising. It was heading straight toward the fog bank. Once in that moist gray mass where the cold sea winds had been vaporized by the warm air of the land, and the blimp would be swallowed up. With its motors muffled there would be no way for “X” to follow. He would lose it and the sinister trail of the Octopus again.

This thought made him desperate. It drove him to consider a plan which was daring to the point of sheer bravado. But there was no alternative now. Either he must take a chance inhumanly great, perform a dare-devil stunt — or lose the Octopus perhaps for weeks or months while his crimes went on. The Secret Agent made his decision there, far above the black, lonely sea.

Grimly he thrust the stick of the gyro forward, brought the craft down toward the bag of the blimp. Down, until he was so close that the wheels of the gyro seemed to hover only a few feet from that great black shape.

THE Agent stared over the edge of the cockpit, stared tensely at the craft below. He saw the woven shroud lines that made a network over the big bag, helping to support the cabin gondola beneath.

The blimp had picked up speed now. Its task accomplished, it was forging ahead at seventy-five miles an hour. Agent “X” swung his gyro slightly ahead of the other craft, came down again till the gyro’s wheels were almost on a level with the top of the big bag. He tested the controls, found them stable. Then resolutely he climbed over the side of the cockpit. The gyro swayed, but did not veer from its course.

Agent “X” stepped on the stubby single wing of the gyro, got down on hands and knees and slid his legs quickly underneath.

He reached up, gave the throttle a deft touch, slowed the gyro’s motor a fraction. The blimp began to catch up. Agent “X” slid down perilously to the gyro’s undercarriage. He snaked his body lower. Twisted beneath the gyro’s fuselage, gripped a cross piece.

Over his shoulder he could see the dark blot of the great blimp. Its bag seemed gigantic now. It was like some great devouring monster of the air. The Agent lowered his feet, hung by his hands.

The nose of the blimp slid underneath him slowly. The gyro’s speed was almost synchronized now. He hung as the blimp’s bag slid forward foot by foot. An air current made the gyro bob once. Ten feet suddenly separated “X” from the blimp’s bag. He was hanging in space between the two crafts. Another air current swung the gyro down. For a moment it seemed that the wind-vane plane was going to crash on top of the other.

Then Agent “X’s” feet touched the thick fabric of the blimp’s back. It was similar to the back of some great pachyderm. He reached down with one hand, grabbed a shroud line, let go of the gyro’s landing gear.

He crouched clinging to the top of the blimp as the gyro continued to sail on. Slowly it slid backwards as the blimp’s speed out-distanced it. Once the air wheels of the gyro did touch. A slight shudder passed over the helium filled bag beneath “X.” It might have been attributed to a gust of wind. The gyro fell away in the darkness behind, sacrificed as he had sacrificed the Oriole.

“X” had accomplished the seemingly impossible. He was alone on the Octopus’s strange craft.

Chapter XXIV

AS the blimp nosed into the fog bank like a great fish, Agent “X” began the desperate climb down over the craft’s side. The clutch of the wind was terrific now. A steady stream of cold, moist fog whipped against his face. The fog was like the slimy tentacles of an Octopus trying to snatch him away to death. But the Agent moved carefully, inch by inch, foot by foot.

He made sure of each hold before he let go the one he had. The fog was a blessing in a way. It was so thick that it veiled completely the faint light of the stars. It cloaked his movements in an impenetrable veil of blackness.

He came to the maximum bulge of the blimp’s bag, began to work inward. Before him, along the slanted shroud lines, he saw the faint glow of a small light. It was forward, toward the blimp’s control room.

“X,” too, worked forward. The light came through a small port in the gondola’s side. “X” located one of the two motors that propelled the craft. It was slightly away from the side of the gondola, giving the propeller room to revolve. “X” avoided those terrible whirling blades, one flick of which meant death.

He marveled at the quiet efficiency of that muffled port motor.

He could hear the faint movement of valves now, hear the drumming swish of the propeller. He worked behind it, climbed down to the motor nacelle, groped cautiously in the darkness.

A six-foot, steel catwalk led from this nacelle to the cabin, facilitating repairs while the blimp was in the air.

“X” lowered himself to the catwalk, felt along it, found a door in the side of the cabin. His heart beat faster. There was a handle on the door. It wasn’t locked. He turned the handle, opened the door, stepped inside. He was now in the very stronghold of death.

A short, narrow corridor, lighted by one tiny bulb went to right and left. There were two doors along the side of this corridor, another up forward.

Agent “X” cat-footed toward this forward door. Inside, the blimp was constructed differently from any he had ever seen. It had been built by an unusual man for unusual purposes.

“X” came to the door at the end of the corridor, opened it.

Silhouetted against another bulb above the blimp’s instrument panel, a man was standing. Rigidly as an automaton he held the controls that guided the blimp through the air. His eyes were fixed on the dials before him that were spread across the polished panel in glittering array. The blimp was in the fog now, being flown by instruments alone.

Agent “X” passed through the door, started toward that silent figure in front of the controls, then stiffened. He had heard no sound behind him, but something cold was suddenly pressed against his back. Some one had come along the corridor silently, seen him enter the control room. Death was in that pressure.

With the quickness of a striking snake, Agent “X” reached behind him, knocked the gun from the fingers that held it with a chopping upward blow of his hand. The gun clattered, but the silent man who held it leaped on Agent “X’s” back, bore him to the floor, wrapping fingers around his throat. The man by the controls gave an amazed, stifled cry.

Agent “X” fought like a mad man. These hirelings of the Octopus were amazed at his presence; but to attack was instinctive with them. The other man left his place at the controls, joined his comrade. They did not cry out again. They bent their energies to overpower this human wraith who had appeared so mysteriously out of the night.

But the light of battle was in the Agent’s eyes. He could not, would not, submit to defeat now. He fought tigerishly, fought for the suppression of the most vicious criminal band with which he had ever come in contact.

Ignoring for the moment those fingers around his neck, he lashed out with his fist at the man in front. Knuckles cracked against flesh. The man staggered away. Then Agent “X” deliberately fell backwards with all his might, fell on top of the man who was trying to strangle him. It was an utterly unexpected maneuver.

“X” jerked his own head forward as he struck. He heard the other’s body hit the steel flooring. There was a thud, a gasp. The hands around the Agent’s neck relaxed. “X” bounded to his feet.

THE man who had been at the controls was coming forward again, jerking a gun from his belt. Agent “X” didn’t give him time to use it. His two fists cracked against the man’s face with the speed of descending trip-hammers. The man went down this time to stay.

Agent “X” whirled on the other, saw that he was out, too, a huddled heap across the sill of the control room door. “X” was master of the forward part of the blimp.

But how many others were there? A sudden, sinking qualm affected “X” like a chill. What if the Octopus himself were not on board? What if this robbery had been accomplished by his hirelings alone? Then “X” recalled those broadcasts. This was the Octopus’s blimp. It must be his broadcasting station as well. He must be on board when such a huge robbery as this was underway.

“X” took one look at the controls. The altimeter read two thousand feet. Its needle showed that the blimp was still level. The compass was steady. The craft could be safely left alone for many minutes. The steady wind would not make it change its course.

Agent “X” stepped over the body of the man near the corridor door. He walked down the corridor silently, eyes alert, gas gun held ready. The strange stillness of the big craft amazed him. The smooth throb of the motors, the faint rhythmic swish of the propellers were the only sounds.

Quickly, silently, Agent “X” opened the first door he came to. There was a small flashlight in his hand. He turned it on. This room went the full width of the gondola. Stout metal beams crisscrossed it. Suspended from the beams was a squat, compact piece of mechanism, an electric hoist, geared to tremendous power. Agent “X” gave an exclamation.

In the center of this chamber, raised above the level of the floor, was the black, mysterious car in which the Mandel child had been whisked from his home.

It was like the spy cars suspended from Zeppelins during the World War. The mystery of the kidnaping was explained. The blimp had hovered above the Mandel home, motors slowed till the craft was stationary against the wind. The car had been lowered to the sun roof. The child had been snatched from his bed. Then the car had been raised on the hoist, the motors of the blimp started so that the car plunged ahead.

There was also a grappling hook on a moveable beam swinging from the hoist. Agent “X” stepped across the floor. At his feet, piled carelessly against the metal wall, was the five million in gold taken from the Morencia.

He left the room, walked silently toward that other door. Coming close, he saw that there was faint light around it.

With fingers tense as talons Agent “X” reached for the handle of the door. The mystery of the Octopus was at last to be solved.

Quietly as a guest entering some room where his host expected him, Agent “X” pushed through the door. There was a brilliant overhead light here. The room was filled with complex machinery, and, at a desklike table in the center of the room, a lone man sat.

Agent “X” drew in his breath with a shudder of amazement. Prepared as he was for a surprise, he was not prepared for this. For the man at the table desk was Professor Norton Beale, the great criminologist.

Beale raised his head, gave a slight start, then sat rigidly, arms spread before him. His leonine head, his broad shoulders, gave an impression of power held in leash. His eyes behind his glasses met those of the Agent calmly.

The Agent’s gun was steady. His own eyes were steely bright.

The whole incredible drama of crime was climaxed by this quiet man sitting before him. A great criminologist turned criminal. A man who had spent his life fighting crooks, now the master crook of them all.

Looking at that huge, intellectual head, Agent “X” realized that here was a man led astray by strange forces. A fierce will, a suppressed thirst for power that the profession of criminology did not bring him, a desire to show the surpassing brilliance of his mind by a mad game of life and death with Society itself, had urged Beale on.

FOR nearly fifteen seconds the Octopus did not speak. A lesser man would have leaped to his feet in amazement at the sight of this unexpected visitor where no visitor seemed possible. But the machine-like brain, the steely nerves of Norton Beale were under perfect control.

He studied the Agent’s face calmly, intent. Then with a magnificent show of aplomb, Beale removed his eye glasses, wiping them with a handkerchief he flicked from his vest.

“X,” anticipating some trick, waited tensely. Beale spoke at last.

“This,” he said, “is an unexpected pleasure. Whoever you are I compliment you sincerely.”

“X” crossed deliberately to the table, took a chair on the opposite side from Beale, gun still centered on the other man’s forehead. Beale studied the Agent’s hypnotic, burningly intent eyes. Then he threw back his head and laughed suddenly. He laughed as though at some uproariously funny joke. “X” wondered if the man were slightly mad. But there was real mirth in the professor’s laugh. It was the mirth of a man who can view a situation with scientific impartiality. Beale spoke, again.

“You needn’t introduce yourself,” he said. “There’s only one man who could have accomplished this. Again I compliment you, Agent “X.” I’ll be interested to hear how you got away from my board of directors, how you survived the fire and explosions in which they reported to me you had died.”

There was maddening calmness, a smug tone of self-complacence and power in Beale’s voice. Faced with the last person in the world he had expected to see, faced with his most relentless enemy, Beale still behaved as though he were complete master of the situation.

There was no humor in the eyes of Agent “X.” He spoke quietly.

“Even if you hadn’t spread terror over the whole county, Beale — even if your employees didn’t go around killing, robbing, kidnaping, extorting, I would put you in prison for the murder of one man. You made a mistake when you had my detective, MacCarthy, killed, Beale.”

“And you, Agent ‘X,’ made a mistake when you first undertook to hinder my work. Even now, when it seems that victory is yours, you cannot win.”

Beale ceased speaking. His eyes glittered. Agent “X” took something from his coat pocket. It was a small black box hardly larger than a pack of cigarettes. There was a tiny lever at one end. The Agent’s finger poised over this lever. He smiled at Beale grimly.

“I’ve knocked out two of your men, Beale. You may have many more on this ship. You may have secret alarm signals. Help may be on the way this second. But, if you make any such move, neither you nor any of your men will live. There’s enough explosive in this box to annihilate us both, destroy this ship and everything in it. Force my hand and I’ll use it to rid the world of a master criminal.”

Beale shrugged, then chuckled softly. “Don’t be impetuous, Agent ‘X.’ When you reach my age you’ll see that there are times for violence and times when it is futile. You’ve misunderstood my meaning. I’ve no other help on this airship. A pilot, an engineer and myself are all it carries. Its mechanism is automatic. It is not even equipped for battle. You say you have overcome both my employees. Very pretty — but I still say your victory isn’t won. Did it ever occur to you that no one in the whole world will believe you when you tell them I’m a criminal?

“Did it ever occur to you that in trapping me you have only tasted the final sting of defeat? Turn me over to the law — and I’ve only to say I’m a victim of Agent ‘X.’ I’ve only to state that you yourself are the Octopus; that I’ve been fighting you tooth and nail, and that you’ve taken me prisoner. You understand now, Agent ‘X.’ We have waged a battle of wits, and I take the final trick.”

Agent “X” nodded silently. There was truth in every word Beale said — appalling truth. The man had played his cards so well that he was above suspicion! Not even the members of his own corporation knew him. For seconds Agent “X” did not move. His shoulders began to droop dejectedly. Then he took a cigarette case from his pocket, selected one and passed them across to Beale.

Beale’s eyes glittered as he stared at the cigarettes. He spoke with sudden amusement.

“If I should disappear from sight for more than a week, Agent ‘X’—if some one should take a notion to — ah — murder me — there are certain papers in the care of a friend of mine which will be opened. These papers state that I am being pursued and threatened by a dangerous and fiendishly clever criminal; a man who calls himself the Octopus. I have even intimated in these papers that Agent ‘X’ may be the Octopus. You will realize by this that my death would be no triumph for you.”

“X” spoke quietly. “I am not a murderer, Professor Beale. Have a cigarette?”

Beale smiled, shrugged, selected a cigarette and made use of the match that “X” preferred. The professor puffed, savoring the cigarette and seeming to find nothing wrong with it. But in a moment the glitter of his eyes became less bright. His head began to nod. The complacent look faded from his face.

Slowly, calmly, the great criminologist and master criminal fell sidewise in his chair, slumping to the floor. The harmless narcotic which “X” had administered to him in the cigarette would keep him unconscious for many minutes.

A cautious search proved to “X” that Beale had told the truth. There wasn’t another living soul on board the blimp outside of Beale himself and the two whom “X” had knocked out.

“X” returned to Beale’s chamber. He studied the complex apparatus it contained. Here was one of the moat elaborate radio and television broadcast stations “X” had ever seen. Here were the sensitive instruments by which Beale exerted his influence over a mighty crime empire. “X” studied, tested, made notes. Then he went into the blimp’s control room and changed the wheels and levers until the airship began to climb.

Up out of the fog bank it soared like a great monster, up till it had reached an altitude of several thousand feet. Then “X” headed it in a northwesterly direction, toward the lonely, far-off Adirondack mountains.

IT was twenty-four hours later that the Octopus’s sinister board of directors met again. Broadcasts to the secret radio receiving sets of each had informed them that another board meeting was scheduled. A new disbursement of assets to stockholders was to be discussed. That, and the proper investment of a large profit which the corporation had just taken in.

The country was still seething with the news of two crimes. The Mandel kidnaping and the theft of the gold from the liner, Morencia. These two appalling events had followed each other in the same week. Both had shocked profoundly the police and the citizens of the country. The kidnaping had brought terror to hundreds of homes. The theft of gold threatened to have international complications. But the Octopus’s directors were pleased. In both crimes they saw the hand of their master.

Quietly at the appointed time they took their places around the boardroom table. Even Van Camp, the criminal lawyer, was there now. He had quite recovered his composure after the narrow escape he had had at the hands of Agent “X.” He had explained how he had been drugged. The corporation members felt secure, now, safe in the power and efficiency of their vast organization.

The doors of the television cabinet opened. The masked face of the Octopus appeared. He spoke in the precise tones with which they were all familiar.

“Greetings, gentlemen!” he said. “We have much to discuss tonight. Business has been extraordinarily good this week — just as it has during the whole month past. I am going to ask Mr. Sullwell, our treasurer, to mention briefly the outstanding deals we have engaged in — and to state what the profits from these deals have been.”

In dry tones Sullwell enumerated a list of robberies and other crimes which had occurred in every State in the union and had netted over two million dollars. The image on the screen smiled.

“Good! Thank you, Mr. Sullwell! The division of profits will be the main subject under discussion tonight. But, there is another little matter to be attended to first.”

The Octopus paused. The board members stiffened, remembering that the last time the Octopus said this there had come the strange disclosure of an imposter in their midst. Surely that could not have happened again. They looked at each other uneasily. The Octopus continued.

“Yesterday some of our employees, acting under my instructions, took prisoner a man so important to us and to society that I asked two of our members, Mr. Kilrain and Mr. Sullwell, to bring him here. Many of you must have heard the name Norton Beale. Beale has written books and has helped the police. He has been a thorn in the flesh of people like ourselves for years. He is our natural enemy. This man is a prisoner of our corporation now. Ring for an attendant, Mr. Sullwell, and have him brought in.”

The evil promoter pressed a button and one of the corporation’s black-shirted men entered. A moment later Professor Norton Beale was ushered into the room. Two black-shirted attendants gripped his wrists; but this time nippers were not used. Beale’s wrists were handcuffed directly to those of his captors.

The eyes of the man on the television screen seemed to burn into Beale’s, as though he could see him standing there. The voice in the loudspeaker was ironic.

“Norton Beale, gentlemen — a man who has hounded criminals all his life! A super-scientific sleuth who is responsible for many police activities against the underworld. Indirectly he has caused the deaths of many of our friends. I consider it fortunate that he has fallen into our hands. What shall be his fate, gentlemen?”

AGAIN cries of “death” went up. Hatred glared on the faces of those who stared at Beale, hatred and fear of a man the Octopus said was their enemy. The Octopus spoke once more.

“The prisoner we had here last week escaped the clutches of our official torturer. That must not happen again. Let Beale be taken to room 13 and given into the hands of poor Waldo’s successor. I recommend that the embrace of the Iron Virgin be used to teach Beale that he cannot fight such a group as ourselves with impunity.”

Cries of approval filled the room. The face of the stocky prisoner went white. A sudden light sprang into his eyes. He spoke for the first time, spoke huskily in a voice that held deep fear.

“Gentlemen,” he said, “you are being tricked again. This man you see on the screen before you is an imposter. He is Secret Agent ‘X’ taking my place. He was not killed in the fire. It was he who called you here — not I. I was brought here a prisoner. He is having his revenge. I am the Octopus.”

A stunned silence followed these words. Then came snarls of derision, cat-calls of disbelief.

“Death to the liar! Kill him!” the board members howled.

When the wolfish clamor had partially subsided, Beale’s voice rose again, a quavering note in it now.

“It is true, gentlemen! I am your leader! It was necessary that I keep my identity hidden. The issues at stake were too big. But now you know who I am. Free me and we can go on as before.”

Again cat-calls drowned his words. Beale’s own statements were being hurled back in his teeth. No one would believe that the famous criminologist and the Octopus were one. But Beale held up his hand, his voice grew frenzied.

“I have proof, gentlemen — proof that I am telling you the truth! Each one of you bears on his chest in invisible tattooing the tentacles of an octopus. That was the system worked out by me, agreed upon when we first organized. I carry a design of the creature’s beak. I anticipated that a time might come when I would have to identify myself to you. Now is the time. That man on the screen is an imposter. Last night he took me prisoner, took the gold from the Morencia away from me. Not content with this he wanted to have me tortured, killed by my own men.”

A sudden silence descended on the room now. Eyes stared at the face of the man on the television screen, stared back at Beale.

“Let us test this man’s words,” said Sullwell. “If he bears the head of the Octopus on his chest he is what he claims to be.”

Every man about the table was standing now, faces grim and strained.

“Take him out to the mirror. I appoint three of you as a committee to verify his words or expose him as our enemy.”

THE three named by Sullwell started for the door, then stopped dead in their tracks. A member of the board gave a scream of fear that was like a tortured clot of sound in his throat.

For the door of the boardroom had mysteriously opened. The corridor outside was black with men.

Federal men, detectives, blue uniformed cops from the Cicero police. The foremost of them carried riot guns and sub-caliber rapid firers. Others held drawn automatics and tear gas bombs. A grizzled head of the federal men spoke.

“Kidnaping’s a racket Uncle Sam is interested in. You guys have kidnaped, among other things. If any of you make a move, we’ll mow you down.”

Fear alone sent one of the criminal boardmen plunging for his gun. He went down under a snarling stream from the rapid-flrer. He kicked a moment and lay still.

“That goes for the rest of you,” said the grizzled federal man. He turned to Professor Beale, whose face displayed an ingratiating smile. “You—” he started to say. But Beale interrupted him.

“Good work, sir!” he said. “You were outside! You must have heard me trying to save myself from these devils by bluffing. It was the only way — but I doubt if it would have succeeded. I was only stalling. They’d have come to their senses and murdered me, realizing that Norton Beale could never be a criminal.”

In the excitement, the ghostly presence on the television screen had been momentarily forgotten. Now the voice came from the loudspeaker again.

“Norton Beale is a criminal! Norton Beale is the Octopus — the man who formed a criminal corporation in this country, the man who engineered the Mandel kidnaping, the theft of the gold from the Morencia and a dozen other crimes. You heard his confession. Now put him to the test. Go behind the mirror in the corridor. Have Beale walk toward it. The secret insignia, the head of the Octopus on his chest will show. That is concrete proof that all his lies can’t overcome.”

Beale lifted his voice in shouting denial. The federal man and two others took him by the arm.

“Sorry,” the federal man said, “but we were tipped off. We came here this afternoon and hid before any of you guys arrived. Somebody who knew all about it tipped us. So far, everything he’s said has panned out. If you’ve got that thing on your chest you’ll have to stand trial.”

They took Beale out of the room. Ten minutes passed while those around the board table waited under the threat of police guns. Then Beale, shaken, his face putty-colored, was brought back. His own cunning method of identification had trapped him. He bore the mark of the Octopus on his body.

“Slip the cuffs on him along with the others,” said the federal man. He turned, faced the screen. The lips of the image moved again.

“You will find the Mandel child in Beale’s country place in the Westchester hills,” the image said. “The five million in gold from the Morencia will be in the blimp anchored on his estate when you get there.”

An instant of silence followed, breathless in its portent, while the eyes of the man on the screen seemed to bore into the room with an almost supernatural light. Then the strange voice sounded once again.

“Secret Agent ‘X’ signing off,” it said. “Good night, gentlemen.”

Slowly before their eyes the image faded. A sound came from the loudspeaker, then. It was a whistle — the strange, uncanny whistle of Agent “X,” at once eerie and melodious. That, too, faded gradually as the image had done; and the only sound in the room was the hoarse breathing of tense, excited men.