Deep Fire Rising

ABOARD THE SEA SURVEYOR II THE PACIFIC

In the twenty hours since his conversation with Ira, Mercer bounced from Area 51 to Vegas for a commercial flight to Hawaii. From there he hitched a ride on an air force cargo plane headed to Guam. He was met there by navy aircraft carrying crew and mail to the carrier USS Ronald Reagan. An aged Sea King helicopter finished the last leg of his journey to the research vessel. Lasko’s name and position carried considerable weight with the military and the transfers had gone off without a hitch.

From the air, the Sea Surveyor looked like any other scientific vessel, with her superstructure hunched over her bows, a long open deck at the rear and an A-frame derrick hanging from her stern. Two boxes the size of shipping containers ate some of her deck space. Mercer figured these housed science labs and the topside support facilities for the bright yellow submersible that sat below the crane. The ship’s helipad jutted awkwardly from the back of the superstructure two levels above the main deck and required all the pilot’s concentration to land. He held the chopper just long enough for Mercer to dodge out of the aircraft and catch his bag and some other gear from a crewman.

Gale-force rotor wash whipped Mercer as the long-range chopper eased away from the pad and thundered off to rejoin the Reagan. A moment later a man in his late forties appeared from a nearby door. He wore a white tropical-weight uniform with short sleeves and gold epaulets at the shoulder. He had a slender build and wasn’t more than five feet seven, but his graying hair and the steadiness of his gaze gave him a strong physical presence.

“Philip Mercer?” he called a bit suspiciously, as if he was expecting someone else choppering out to the middle of the ocean. “I’m Jon Carlyle, third officer. Welcome aboard.”

“Thank you.” They shook hands and Carlyle led him into the superstructure. The air-conditioning beat back the humidity and heat.

“We were startled by the radio message this morning from the navy that they were flying you out. I’m sorry, but I wasn’t expecting a civilian. You are a civilian, right?”

Mercer was still getting comfortable with using his title and the startled looks it invoked, but he needed to establish his credentials early. “Actually, I’m special science advisor to the president.”

“Of the United States?” Carlyle was suitably impressed.

“That’s the man. I’m here under the authority of Admiral Ira Lasko, the deputy national security advisor. Not only were you at the right place and time to monitor the sinking of the USS Smithback, but until the navy can get a salvage ship from San Diego, you’re also the only one with the proper equipment to investigate the wreckage.”

“Ah, we weren’t told you’d commandeer our sub for a survey.”

“Your captain — Jacobi, I think his name is — should be on the ship-to-shore right now getting orders to assist me in any way. And in case you’re wondering, the government’s picking up the tab.”

“What exactly are we supposed to do?”

“You know the circumstances surrounding the Smithback’s sinking?”

“I was on watch when her distress call came through,” Carlyle replied. “She said she hit an iceberg. At first I thought it was a crank, but now, well, I have a theory.”

Mercer waited.

“It was the last words, about the sea catching fire. I think she hit a container that fell off a freighter and whatever was in it caused the blaze.”

“That’s our assumption too.” Mercer had decided not to mention anything about Tisa Nguyen and her predictions and would have proposed the container theory had the third officer not thought of it already. He’d also created a plausible cover for the urgency of his mission. “However, the navy needs confirmation. There have been unspecified terrorist threats against our ships in the Pacific, and if this turns out to be something other than an accident…”

“They have to know right away so they can take appropriate steps,” Carlyle finished for him. “I was in the navy for twenty-one years. I know how it goes and personally I’m glad we’re here to help.”

“Thank you, Mr. Carlyle.”

“Jon.”

“Jon. People just call me Mercer.”

“Let’s get you settled, Mercer, and come up with a plan to survey the wreck.”

Mercer stowed his meager luggage in the cabin assigned to him and took a brief shower. He stepped from the tiny bathroom wearing only a towel and was about to toss that on the bed when he saw a raven-haired woman standing in his doorway. He recalled closing the door minutes earlier. She wore sandals, tight shorts, and a T-shirt that sweat kept plastered to her skin. It was obvious that she wasn’t wearing a bra. She radiated an earthy sexuality that Mercer imagined would captivate most men.

She appraised him for a moment. “That was quite an entrance.”

“The helicopter?”

“That, too.” The flirtation went from her voice. Her eyes hardened. “I’m Spirit Williams, one of the scientists who’s losing their opportunity to work because of you.”

“I—”

“There’s nothing you can say, so don’t. I’ve spent a lifetime to get aboard this ship, and I wanted to say thanks for screwing it up for me.” She wheeled away and was down the hall before Mercer fully grasped what she’d said.

He didn’t go after her. It would be a waste of time. He knew the type. A scientist, probably still working toward her doctorate, so dedicated to her work that anything, no matter how serious or important, was a distraction she refused to tolerate. Such narrow-minded focus served scientists well in their own world, yet made many insufferable to the rest of society. He expected the rest of the science staff on the Sea Surveyor would treat him in a similar fashion. With any luck he’d complete his mission before seeing her or any of the others.

Ten minutes later, Mercer found the mess hall and saw his luck had already run out. Spirit Williams was in the mess hall with Jon Carlyle and a young blond man in diving trunks and a garish Hawaiian shirt. Her leg was pressed against his, and she was drinking orange juice from a glass in front of him. Noticing the ring on his hand, he assumed they were married, although she wore no jewelry.

“Ah, Mercer.” Carlyle stood. “Let me introduce one of our sub drivers, Charlie Williams.”

The tanned surfer stood. “Call me C.W. This is my wife, Spirit.”

“I’ve had the pleasure.” Mercer took the fourth chair at the table. A mess steward asked if he wanted anything. Mercer took coffee.

“I met Mr. Mercer earlier and told him I didn’t appreciate his presence on the Surveyor,” Spirit said acidly. “I suspect he’s here as part of a government cover-up. The navy was probably doing some illegal research, killing whales with sonar like they did a few years ago off Long Beach, and something went wrong. Now he’s going to hide the truth.”

“He’s here to find out why a lot of brave sailors died two nights ago,” Jon retorted. He’d had his fill of Spirit’s rancor. The vessel’s crew had no real interest in what the ship did once she was at sea, but the researchers had tight funding and guarded their time on board jealously. Even a few days’ delay was a colossal waste of their time and resources. They hadn’t stopped griping since getting the news, and C.W.’s wife had been the most vocal.

“Their souls have crossed,” Spirit replied. “They should be left to rest. Sending people down there to gloat over their remains is ghoulish.”

“Mr. Mercer isn’t here to gloat. He’s here to get answers so more sailors aren’t lost.”

“They knew the risks when they joined the navy. Dying’s part of their job.”

Carlyle’s face grew red. “Defending our country is their job.”

“Oh, I see.” She became even more sarcastic. “Dying is just a fringe benefit.”

Mercer caught C.W.’s eye. The submersible operator showed no interest in restraining his wife. He’d heard her in action before and knew to stay out of the line of fire.

“Now, see here,” the normally unflappable officer thundered. Since the loss of the Smithback, his admiration for the navy and its men had been rekindled. Before he could continue, four other men entered the mess room.

Carlyle glared at an unrepentant Spirit, wiped his brow with a handkerchief and made the introductions. One of the newcomers was a second sub pilot. The other three headed the support staff.

“You’ll have to go, sweet,” C.W. told his wife.

Like flipping a switch, her temperament did a complete reversal. She smiled at the assembled men and gave C.W. a long kiss on the mouth. “Come get me at the lab if you’re diving today. I want to be in the van. Love you.”

“Love you, too.”

If Jon expected C.W. to apologize for his wife’s behavior, he had a long wait coming. The seconds grew.

Mercer realized no one would cut the silence, so he cleared his throat. “Okay, down to business. Jon may have told you I’ve been sent here to discover what happened to the Smithback. It seems we’re all under the same impression that she struck a container that split and whatever was inside burned. The navy wants me to verify this hypothesis by physically inspecting the wreck. Have you pinpointed it on the seafloor?”

Jim McKenzie, who headed the team, spoke up. “We found her on side-scan sonar about ten hours after reaching the area. She’s directly below us now in nine hundred eighty-eight feet of water.”

“That seems kind of shallow,” Mercer said. “We’re in the middle of the Pacific Ocean.”

“We’re atop a subsea plateau that rises from the abyssal plane. Had the Smithback sunk fifty miles to the north, she’d be two miles down and unreachable by anything we have on board. Bob’s rated for two thousand feet, and our two ADSes can safely operate at one thousand. Just so you know, Bob is the name of our submersible. It’s what she does when she resurfaces. Just bobs in the ocean.”

Mercer smiled. “I have a friend who named his dog Drag because that’s how he takes his walks. What’s an ADS?”

“Atmospheric Diving Suit. Also called a NewtSuit. Think of it as a one-man submarine with arms and legs. It keeps the operator at sea-level pressure so we don’t have to bother with decompression but gives a freedom of movement we can’t get from a larger sub or even an ROV. C.W. helped in their development and is about the best operator in the world.”

“Jim’s exaggerating,” C.W. said to Mercer. “In college I worked part-time in the factory watching a computer-controlled lathe form the suits’ torsos out of aluminum blanks.” He gave a lopsided grin. “But I am the best.”

“How many men can Bob carry?”

“Three,” McKenzie answered. “Pilot and two observers. We do have a problem. We fried one of Bob’s banks of lights doing a test a week ago. At this depth you can’t see an inch beyond the porthole, and our ROVs operate with low-light cameras so they can’t provide enough backup illumination.”

“The solution,” C.W. interrupted, “is that I go down with you in an ADS and use it as a mobile lighting platform.”

“Are the ADSes autonomous?”

“They’re tethered to the Surveyor by a lifting cable and communications lines but don’t rely on the ship for air. Don’t worry,” C.W. added, “we’ve run the NewtSuit and sub together quite a few times.”

Mercer turned to McKenzie. “How long before we can dive on the wreck?”

“Weather isn’t a problem. No storms predicted for days. Batteries are all fully charged and we just replaced the CO₂ scrubbers. We need to fit new ballast plates and charge the O₂ tanks, then run a few tests. Say, five hours.”

“Are you going to want to see the tower too?”

This was the first Mercer had heard of any tower. “What are you talking about?” he asked Carlyle.

“The underwater tower about a mile to the west of us. We found it on sonar when we were searching for the Smithback.”

“What is it?”

“We’re not sure,” McKenzie answered. “It appears to be some kind of underwater oil- or gas-drilling platform. From its sonar image, it stands about eight hundred feet tall and is about a hundred wide at the base. It tapers as it rises. The top is about forty feet square.”

“And it’s completely underwater?”

McKenzie nodded. “The bottom there is deeper than here, about thirteen hundred feet. The top of the tower rests five hundred feet down.”

Mercer had never heard of such a structure. He was familiar with deep-sea drilling even though he wasn’t an oil geologist. An eight-hundred-foot platform wasn’t all that unusual anymore. Some in the North Sea stood over a thousand feet, but all of them were serviced by modules constructed above sea level. What McKenzie and Carlyle were talking about was something entirely new. And as he thought about it further, something else came to mind. As far as he knew, there weren’t any oil deposits within two thousand miles of their current position. One mystery at a time, Mercer decided. He was sure there was a connection between the enigmatic structure and the Smithback accident, but he wanted to see the ship before investigating the tower.

“Let’s check the ship first. What’s Bob’s range?”

“She can stay down for thirty hours or more, but at a top speed of three knots she isn’t exactly mobile.” This came from Alan Jervis, the submersible operator who would actually take Mercer down to the wreck. Jervis was about Mercer’s age, with dark receding hair and gold-framed glasses. “If you want to remain on the bottom and reach the tower, it’ll take us an hour or more because we’ll be bucking a two-knot current the whole way.”

“We’d have to move the Surveyor,” Carlyle said. “C.W. will be tethered to us. To get him over there, we have to reel him up, steam over to the tower, then lower him down again.”

“Is that a problem?”

“No. And with your slow speed, he’d be in position before you.”

“Then that’s what we’ll do,” Mercer announced. No one questioned his authority. “We’ll drop down to the ship first and then check out this tower of yours.”

Mercer tried to catch a nap after the meeting, but the strong coffee and a rattling air-conditioning fan kept him awake. After the first hour of staring at the ceiling, he admitted his insomnia had nothing to do with caffeine or noise. The image of Tisa Nguyen kept sleep out of his grasp. It was her eyes he kept seeing, their depth and their pain. He didn’t believe it was personal trauma. That was something people kept better hidden, at least from strangers.

She reminded him of the subject of a religious painting, a Madonna and Child perhaps, where the beatific Mary looks lovingly at her infant yet in her eyes is the knowledge he would have to die for the world’s sins. Did Tisa know of such sin? Was that why she was convinced the world was ending?

He wondered what she had witnessed to make her believe that. Hers wasn’t general angst about the state of a world racked by wars, famines and other sundry catastrophes the media reported so cheerfully. He was convinced it was something specific, something she and her group alone knew had happened or was about to happen.

She’d all but admitted her group’s involvement with the sinking of the Smithback. No, that wasn’t true, he recalled. She’d only said that something unusual was going to happen in the Pacific.

He had never felt so unbalanced. He felt like he was walking through a minefield holding the wrong map. In the past weeks he’d been tossed a dozen lies, survived two murder attempts and met a woman he couldn’t stop thinking about. Connecting all this was a fiber too thin for him to see, let alone grasp.

Did Tisa Nguyen know about the Smithback being in the vicinity of the tower? Had she not warned him in time and allowed it to sink the way she’d not prevented the death of the woman at the Luxor Hotel? Or was the sinking an unintended consequence? What if the Smithback had wandered into some type of experiment that her group was conducting. Did it have anything to do with Dr. Marie’s experiment in optoelectric camouflage?

He could only hope that some of the answers lay a thousand feet below where he tossed on his bunk.

An hour later, bound by frustration, Mercer gave up on trying to sleep. He donned the coveralls Alan Jervis had provided earlier, used the head as the sub pilot had requested and made his way to the Surveyor ’s fantail.

Bob sat in a cradle under the A-frame derrick. The submersible was painted bright yellow and its hull was studded with auxiliary oxygen tanks, small thruster nacelles and a pair of heavy-duty manipulator arms ending in wicked-looking pincers. Her bow was a single piece of curved Lexan six inches thick. Through the tough acrylic dome, Mercer could see the cramped cockpit. Alan would sit behind and a little above the two observer seats. The interior walls were covered with dials and banks of switches and several flat-screen computer monitors. The little sub was the pinnacle of high-tech deep-sea technology.

Nearby, C.W. worked on an even more unusual piece of equipment, the ADS. The suit was also painted yellow, and the twenty rotator joints made it look segmented, like the body of a corpulent caterpillar. The helmet had a wide faceplate for good visibility, and at the end of the arms were nimble three-finger grapplers.

“What do you think?” C.W. asked with obvious pride.

“Damn amazing. What does it weigh?”

“Over five hundred pounds empty, but the way the suit’s balanced and the fluid in the joints work, it’s almost weightless below thirty-five feet. It’s the next best thing to scuba diving, provided you’re not claustrophobic.”

“How do you work it?”

“Nothing to it.” C.W. snapped open the back of the suit. “I was about to do a systems check. You can do it with me. Hop in.”

It was like stepping into a pair of steel pants. Mercer used a bar attached to the ADS’s lifting cradle to heave himself through the opening. He lowered his feet down into the legs and thrust his arms into the appropriate openings. His head came up inside the domed helmet. When he was settled, he could feel large rocker switches under his feet and several control buttons and toggles next to his hands. The suit smelled of electronics and disinfectant with just a trace of the previous user’s sweat.

“Do you feel the foot pads?” Even with the access hatch open, C.W.’s voice was muffled and distant.

“Yes.”

“They control the thrusters. Put pressure on the back right and the suit moves backward. Try it now.”

Mercer pressed down on his heel and a pair of thrusters attached to his shoulders began to whine.

“Press forward and you go forward.”

He tried it and the small propellers stopped in an instant and began turning the opposite direction.

“Your left foot controls rotation,” C.W. explained. “Back spins you right and forward spins you left.”

Mercer applied pressure and other thrusters mounted on the exoskeleton spooled up to a high-pitched buzz. He then tried out the arms. He’d had thousands of hours operating heavy mining equipment that used joysticks similar to those inside the suit’s arms. It took him just a few minutes to get the feel of the ADS’s controls.

“Shit, man, you’re a natural,” C.W. exclaimed when Mercer reversed himself out of the aluminum suit.

“The controls are pretty logical.” Mercer was impressed. “And you said at thirty-five feet you don’t even feel the mass?”

“It’s amazingly flexible.” C.W. patted the suit’s metal hide. “Muscle power alone moves the arms and you can bend through forty-five degrees. NASA astronauts who’ve tried one of these say it’s better than their space suits, and the pressures we work in are a hell of a lot stronger than the vacuum they experience. If you have the time while you’re aboard, I’ll let you try one on a test dive.”

Mercer smiled. “I’d love to take you up on that, but I don’t think it’ll happen. I expect to be out of here as soon as possible.”

C.W.’s normally easygoing expression faded. “What’s really going on?” he asked. “Are you allowed to say? Was Spirit right about a government foul-up?”

“No, there isn’t any kind of cover-up, though I doubt my word will convince your wife.”

The former surfer chuckled. “It took me all of five minutes to learn that if she says the sky is green, I’m better off not debating her.”

“You must be a slow learner,” Mercer teased, comfortable with C.W.’s mellow demeanor. “I figured that out in five seconds.”

“She is something, huh? I met her at a beach party. I had just convinced this other girl to go back to my place when Spirit walked up behind me. She said that I was a sexist pig and that I had no interest in the other girl beyond her silicone boobs. I turned around to call her a dyke or something, and man, I just stopped cold. I think she felt it too. The only other thing I remember about that night was later, we were in bed and she said something like ‘Better than silicone, aren’t they?’ ”

Mercer smiled at the story, at some level envious that Charlie had been able to transform lust into love. He’d felt that momentary jolt of desire many times, but for one reason or another nothing developed much past a casual affair. Harry White had once told him that getting married is equal parts the person and the timing. One without the other just won’t work. Of course taking marital advice from an eighty-year-old bachelor wasn’t the best idea in the world, but Mercer couldn’t deny the truth in his words.

Many women had come into and out of his life. He didn’t think the problem was with them, so it had to be the timing. Or with himself.

His atypical train of thought was interrupted by the approach of Alan, the sub pilot, and Jim McKenzie, the topside coordinator. Alan tossed a sweatshirt to Mercer. “It gets cold at a thousand feet and we can’t afford the battery power for a heater.”

As Mercer slipped into the garment, the three men went over their predive checklists and made last-minute adjustments with a team of hovering technicians. He noticed Spirit standing on the helipad above the deck. If he wasn’t mistaken, she was staring at him and not her husband. Then their eyes met. Spirit shot him a contemptuous look and retreated into the superstructure. The intensity of her anger was out of proportion with the delay he was causing her research. It felt almost personal.

“We’re all set,” McKenzie announced. “Let’s get you into the can and buttoned up.”

Mercer climbed the ladder leaning against Bob’s curved hull and carefully lowered himself through the hatch, mindful of the thick grease smeared around the coaming to help maintain a tight seal. He stepped first on the pilot’s seat, then contorted himself all the way in so he slid into one of the cramped observers’ positions. In front of him was an array of dials and switches Alan had assured him he needn’t worry about. From his seat, the pilot could control everything except the manipulator arms. A moment later, Alan eased into the sub. He donned a headset and began another predive checklist with McKenzie, who’d already moved into the control van with a handful of others. To Mercer it was like listening to the arcane language of a pilot talking to the control tower, just a series of numbers and indecipherable acronyms.

“Okay,” he announced. “Everything checks out. We’re good to go. We’ll launch first and then they’ll send down C.W. in the NewtSuit.”

“How long’s the descent?”

“Shouldn’t take more than twenty minutes. It’s only a thousand feet. And just so you know, the pressure’s something in the neighborhood of five hundred pounds per square inch.”

“Remind me not to buy property in that neighborhood.”

With a jolt, the A-frame lifted the eleven-ton submersible from its cradle and gently transferred it toward the fantail. Beyond the ship’s stern, the sea was calm and a deep blue found only far from shore. The sky was cloudless. Bob was slowly lowered into the water. Mercer unconsciously took a deep breath when the first waves lapped against the Lexan bubble.

“Never been down like this before, huh?”

“Is it that obvious?”

“Not really,” Alan replied. “Most first-timers are so nervous they don’t stop talking. But no matter what, everyone takes a deep breath when the sub starts to sink.” The pilot switched on his headset. “Jim, my board is clear, go ahead and release.”

There was another jolt as the cables securing Bob to the cradle let go and the submersible floated free.

“And down we go,” the pilot said.

Negatively buoyant because of the ton of iron plates attached to the underside of her hull, the sub slipped beneath the waves. Mercer craned his head to peer upward as water covered the top of the Lexan bubble. The surface of the ocean reflected a wavering mercury sheen. The surface receded from view as the submersible slipped into the depths. For many minutes there was enough light filtering from above to see the surrounding water. Food scraps dumped from the scullery had attracted schools of scavenger fish and the predators that preyed on them. A few of the braver ones paused long enough to determine if the submersible would be their next meal before disappearing into the thickening gloom.

The water acted as a prism the deeper they dropped, cutting the light’s spectrum so that the colors began to separate and fade away. Yellows and oranges vanished first, then reds, until their view was a violet void. And even that faded to blue and finally to black.

“Think we’re alone?” Alan asked after ten minutes.

“I would assume so,” Mercer said, sensing he was being set up by the experienced pilot.

Alan hit a switch to turn on the working set of lights. The sea came alive. The water was far from clear. It almost looked like a snowstorm outside the sub’s protective cocoon. The bodies of tens of millions of tiny creatures slowly drifted toward the abyssal plain where bottom feeders would eventually assimilate them back into the food chain. Fish that had kept their distance from the gawky interloper rushed at the lights. They were still shallow enough for Mercer to recognize the shape of the fish if not the species. The sea’s truly bizarre creatures, the vampire squids, the gulpers, the angler fish, and the others, lived far below Bob’s crush depth.

“I’ve logged more than six thousand hours down here,” Alan said with a trace of reverence. “I never tire of it.” He killed the lights again. “Sorry, got to conserve batteries. I know this won’t be a long dive, but it’s SOP.”

“Thanks for the glimpse. It’s a hell of a place you work in.”

“Depth is eight fifty,” Alan called out, both for Mercer and the men anxiously watching their monitors on the Surveyor.

“C.W.’s on his way down,” Jim McKenzie announced over the directed laser pulse communication set.

“Roger, Jim. We should be on the bottom in six minutes.”

“Confirmed.”

Jervis activated the bottom search sonar, a weak acoustical pulse that rang like an accelerating electronic chime the deeper they fell. Mercer’s chest tightened in time with the tones. He was getting closer to an answer, he knew, only he wasn’t sure what the question had been.

“Bottom in fifty feet,” Alan murmured, his fingers flying over control knobs and switches as he began to trim the sub.

“We’re showing you one hundred ninety feet due east of the wreck,” McKenzie announced over the radio.

A drop of condensation dripped onto Mercer’s face. He’d known to expect it — there was a sixty-degree temperature difference between Bob and the ocean — yet any water inside the sub with so much pressure against her steel hull made his heart jump.

Alan activated the forward thrusters and kicked on the lights once again. Had they not been reduced to half capacity, they still couldn’t have revealed much beyond twenty feet. The water appeared as dense as ink. Mercer peered into the murk, straining to be the first to spot the wreckage of the USS Smithback. The bottom was sandy and showed the undulating ripples of a steady current. It was also entirely featureless. The moon showed more topographic variance.

“There!” Alan said. Experienced in deep dives, he spotted the hulk a minute before Mercer could see the vessel emerge from the darkness.

The wreck of the Smithback rose from the seafloor like the ruins of a Moorish fort long abandoned in the Sahara. She’d sunk only days earlier yet looked decades old, forlorn, forgotten, haunted.

“Jesus. Look at her.”

The USS Smithback had been a military sea-lift vessel, a boxy cargo ship with blunt bows and a square stern. Purchased from the Maersk Line following the Gulf War, the Smithback’s job was the rapid delivery of an entire armor task force of up to sixty M1A1 Abrams tanks. At more than six hundred feet long, she’d only needed a crew of forty-eight. Although Mercer and Jervis were limited to half illumination, they could see enough detail to know that whatever happened to the Smithback could not be explained away by a collision with a shipping container. Mercer couldn’t understand what he was seeing.

The ship’s hull and superstructure had been crushed flat by the impact with the seafloor. This phenomenon wasn’t unusual. A falling vessel could approach twenty miles per hour by the time it reached the end of its plummet, and structural members weren’t designed for that kind of force. Yet the damage to the Smithback was much more severe than either Mercer or Jervis anticipated.

It was as if a giant fist had ground the vessel’s remains into the seafloor. The bow was buried deeply in the silt and her keel had fractured amidships. It was impossible to tell if she was listing because she had so completely collapsed. From the spec sheets Ira had had delivered to Mercer, he knew the Smithback had been ninety feet tall from keel to bridge. The hulk of twisted metal plates resting on the bottom of the Pacific looked no more than a quarter of that. She’d completely pancaked.

The light outside the submersible shifted as C.W. in his diving suit approached the wreck. “What happened to her?” he asked when he saw the extent of the damage.

“We’re trying to figure that out,” Mercer replied. “Let’s start with the bow and work our way back.”

“Roger.”

The nimble NewtSuit lifted away from the hull and swooped toward the front of the ship. Alan maneuvered Bob into place so the combined lights bathed the wreckage in a diffused yellow light. The two sub drivers moved as one as they made their way down the vessel’s length. The ship’s steel skin had wrinkled like an accordion and crossbeams from within the hull had punched through the metal like fractured bones. When they reached the amidships superstructure, Mercer had Alan take them as close to the ship as he dared. Every one of the six decks in the blocky superstructure had been flattened into the one below. Glass from the wheelhouse had exploded out onto the deck and glittered like gemstones. Near the stern they found where bunker oil leached from the hull in dark bubbles. There were only a couple of spots where air pockets vented into the sea.

“What do you think?” C.W. asked after they finished their inspection.

“If I had to guess,” Alan Jervis answered, “I’d say that she was fully laden when she sank and all the air escaped the hull as soon as she went under. That’s the only way she could be going fast enough to cause this much damage. What’s your take, Mercer?”

“Good theory but there’s a problem.” Mercer rubbed his jaw as he considered the implication of what he was about to say. “The Smithback was dead-heading back from Korea. She was empty. Her cargo decks encompassed more than a hundred thousand cubic feet. Even if her loading ramps had been somehow jarred open, it would take time to expel that much air. I think it was something else.”

“Like what?” C.W. asked.

“I don’t know, but I hope the answer’s over at the tower your guys found. Jim, can you hear me up there?”

“We’ve been monitoring your comms,” McKenzie said from the Surveyor.

“We’re going to head over to the tower now. Haul in C.W. and we’ll meet him there.”

“Affirmative. Alan, make your heading two hundred sixty-five degrees. We’ll correct your course for the crosscurrent en route.”

“I hear you, Jim. Two hundred sixty-five.” The pilot lifted the sub away from the wreck of the Smithback and killed the lights. The darkness became impenetrable once again as they moved steadily away from the ghostly hulk.

Alan turned on a portable tape player to drown out the incessant buzz of the forward thrusters. An up-tempo jazz song filled the cramped cockpit. “I’ve dived on about twenty wrecks,” he said after a few minutes. “You see that kind of collapse on older ships. After corrosion eats through the steel, they implode. We found a World War One freighter once off the coast of France. She’d fallen apart like that. Nothing more than a sandwich of decks and rust. But I’ve never seen anything like what happened to the Smithback.”

“I can’t explain it either.”

“But you have an idea?”

“Maybe,” was all Mercer said. Without at least a bit of evidence he wasn’t about to voice his off-the-wall theory.

Jervis flew the little sub by her sophisticated suite of sensors and didn’t seem bothered that he couldn’t see more than a half inch outside the Lexan dome. Mercer had become comfortable in the disorienting environment and settled deeper into his seat. The temperature in the cabin was down to fifty-eight degrees and he was thankful for the sweatshirt. He kept his hands clamped between his legs and still they felt frozen. Part of his chill came from what he feared he’d find at the tower.

Forty-five minutes later, Jim McKenzie called a change in course and warned them they were a thousand yards from the tower. The sonar showed the seafloor was three hundred feet below Bob’s rounded hull. Jervis nosed the little sub downward as they approached the mysterious structure.

“We’ll start at the base,” he said, switching on the external lights. “C.W. can’t dive this deep, so we’re on our own for a while.”

“Okay.”

The first of the tower’s massive legs came into view when they were fifteen feet out. The steel column was at least forty feet in diameter. There didn’t appear to be any anchor mechanisms other than the structure’s massive weight driving it into the seafloor. Fifty feet up from the bottom, bolted girders extended off the leg and presumably attached to other columns. Angled cross members completed the skeletal design. It was like finding the Eiffel Tower in thirteen hundred feet of water.

They circled the tower as they rose, spiraling upward while keeping the sub scant feet from the structure. When they were two hundred feet from the bottom and still a hundred feet below where C.W. could help them investigate, they found the first propeller. The massive five-bladed affair was stationary, but each vane was wickedly curved for maximum efficiency if it began to rotate. In the wavery light it was difficult to tell what the forty-foot propeller was made of, but it appeared to be some sort of flexible material. The navy used malleable props on its quietest submarines to reduce cavitation noises.

“What do you make of that?” Jervis asked without expecting an answer.

Nestled within the labyrinth of structural steel behind the propeller was a large enclosed capsule at least twice the size of the submersible. Mindful of the thruster nacelles attached to Bob, Alan nosed the sub between some of the larger struts to get a closer look at the strange construction. An axle ran from the propeller into the rounded box. From its bottom, several large pipes dropped into the gloom. Mercer and Alan hadn’t noticed the pipes on their way up.

“It’s like a giant windmill,” Mercer said. “Notice how the blades face into the prevailing current. Water passing over the blades makes them turn.”

“To do what? Does it pump something out of the ground, like oil?”

“I don’t know. Back us out and let’s see what’s above us.”

They found three more of the large propeller and housing assemblies as they ascended. At seven hundred feet below the surface, C.W. waited for them in the bulbous ADS.

“How many of these things are below us?” he asked through the comm link.

“Four.”

“And there’s two more above us.”

“Did you find any kind of storage tanks?” Mercer inquired.

“Just the propellers and their support mechanisms. None of them are turning right now and I think they’re all linked by pipes. One thing I did notice is the water’s colder around the thinner of the pipes.” Thinner was a relative term. The network of plumbing that connected the machines had a minimum diameter of five feet.

“How much colder?”

“Five to seven degrees, according to the suit’s sensors.”

Mercer felt he was on the trail of that first scrap of evidence he needed. “Can we check temperatures at the base of the tower?” he asked Jervis.

“No problem. Remember, Bob’s designed for scientific exploration. I can get temperature, pressure and salinity readings every fifteen seconds.”

“C.W., stay here,” Mercer ordered, gripped by excitement. He was pretty sure he knew what they’d found. There was a measure of risk staying this close to the tower, but he felt justified. “We’re going to need you when we come up. I want to open up one of the propeller’s housings to see what’s inside.”

“I’ll work at it while you’re down,” C.W. said in his surfer drawl.

“No. Wait for us to come back.”

“Oh, sure, man,” he said, chastened by Mercer’s sharp tone.

Alan Jervis eased the sub away from the tower and sent the craft toward the bottom again. “What are you thinking?” he asked after they’d sunk through a thousand feet.

“Turbines can be used for three things,” Mercer said. “Pumping something up, injecting something down or generating electricity. There aren’t any transmission lines so this rig isn’t producing power. We didn’t find any reservoirs to hold something being pumped from the seafloor. That leaves us something being pumped down into the ground.”

“Makes sense, but wouldn’t there be reservoirs of whatever was being injected?”

“Not if it were seawater. Or if the system was a closed loop.”

“Which one do you think it is?”

“In a sense, both.”

“You gonna explain that?”

“Ever wonder how they keep hockey rinks frozen?”

Jervis chuckled. “I grew up in Arizona. Hockey wasn’t much of a priority.”

“The Coyotes play in Phoenix,” Mercer pointed out. “It’s done by pumping salty water — brine — through a system of tubes under the ice. Because of the salt, the brine remains liquid below thirty-two degrees. The supercold pipes keep the ice frozen and voilà, slap shots in the desert.”

“Hold on,” Jervis interrupted, “we’re coming up on the bottom. The water temperature’s dropping faster than it should. It’s down four degrees in just fifteen feet.”

The lattice of struts and supports near the tower’s base wouldn’t allow them to get close to the pipes coming down from the turbine housings. Instead Mercer had Jervis circle the structure in ever-widening loops. Revealed under the lights, the bottom appeared featureless. The silt had a green cast in the artificial glow, and the blizzard of drifting organic material made it impossible to see more than a few feet. Still, Alan maneuvered the sub like an expert, keeping her nose scant feet above the abyssal plain.

“What’s that?” he asked after a few moments. “A crater?”

“Not sure,” Mercer said, but he was.

It took several minutes to cross over the crater from rim to rim. The bottom-profiling sonar showed it was a hundred feet deep. Mercer did the figures in his head. The crater had a volume of almost half a million cubic feet. He asked the pilot to hover at the edge of the large pit.

“What are we looking for?”

“Just hold it steady.” Mercer took hold of the manipulator controls.

“Hey, you can’t do that!” Jervis protested as the arms unfolded from their stowed position.

Mercer flexed them out straight, testing how his movements on the joysticks affected the joints and grapplers. “I’ll pay for any damage.”

In seconds he had the system figured. Like the controls for C.W.’s diving suit, Bob’s manipulator arms felt familiar because of his years working with mining equipment. Mercer returned one of the arms to its default attitude and moved the other closer to the crater’s rim.

“What’s going on down there?” McKenzie called over the comm.

“I want a soil sample,” Mercer said.

He eased the grapple hand into the ooze, causing a small avalanche of mud to slide below the submersible. Although there was no feedback resistance on the joysticks, Mercer could tell the arm hit something solid. A silvery bubble burst from the mud, and in the cavity he’d excavated he could see a strange white mass.

“What is that?” Jervis asked.

“Ice.”

“What? That’s impossible.”

Mercer turned to look at the pilot. “And yet there it is. The rig is a giant heat pump.”

“What for? This thing doesn’t make any sense.”

“Hey, guys,” C.W. called from above, his voice metallic from the echo within his suit. “Something’s happening up here. The blades are starting to turn. Wow.”

“What is it?” Alan asked quickly.

“Current can’t be more than a knot or two, but this thing’s spinning like it’s in a freaking hurricane.”

It took Mercer a second too long to digest what C.W. had just said. He’d been looking at the tower one way, ignoring the implications of another point of view. As he realized his mistake, his eyes widened, and yet when he spoke his voice carried a steel edge. “C.W., secure yourself to something. Grab on to the tower. Jim, can you hear me up there?”

“I’m here, Mercer, what’s going on?”

“We’re sitting on top of a methane hydrate deposit. That’s what sank the Smithback. You guys have got to get out of there.”

“What are you talking about?”

“Methane hydrate. The last great source of fossil fuel on the planet. It’s a gas kept locked in ice by the temperature and pressure on the seafloor. It’s normally stable, but I think this tower’s designed to cause the hydrates to melt. The gas is about one hundred fifty times the volume of its solid state. If the deposit is big enough, that much methane is going to cause the ocean to bubble up like champagne. If it’s bad enough, it will reduce the water density and the Surveyor ’s going to lose buoyancy. She’ll sink like a stone.”

“Is it erupting now?” McKenzie asked, understanding the danger.

“It’s going to.” Mercer’s first assumption about the tower being a heat pump had been correct. Only now he realized it wasn’t forcing cold brine into the soil to keep the hydrate stable, it was designed to draw it up in order to dissipate the chill in the warmer shallower water and trigger a gas burst.

The Smithback must have sailed through an eruption and struck an enormous chunk of hydrate ice that hadn’t dissolved on its journey to the surface. But that damage hadn’t caused her to sink. It was the change in water density. Ships stay afloat because they weigh less than the volume of water their hulls displace. In the case of the Smithback, the frothing mix of gas and water wasn’t dense enough or didn’t weigh enough to support the vessel’s mass. She began to weigh more than the water she displaced and lost buoyancy. At some critical point she would have dropped from the surface so suddenly that no one could have saved themselves. The Smithback would have careened toward the seafloor much faster than normal. The ship could have been doing fifty or more miles per hour when she hit bottom. No wonder there wasn’t much air escaping the hulk. It had blown from her when she impacted.

And the fire reported just before she sank? Methane hydrate, even in its ice form, was extremely flammable. The air around the ship would have been saturated with gas, and even the smallest spark would have set off a catastrophic explosion. Mercer purged the horrifying image from his mind, that of a vessel engulfed in flames while her crew vainly tried to understand why the small amount of damage from the impact was causing their ship to sink. He refocused his mind on his own impending predicament.

Over the comm link, Mercer could hear hurried orders being shouted in the topside control van. “We have to haul C.W. back aboard,” McKenzie protested.

“I don’t think you have time.”

Mercer pointed to where he wanted Jervis to guide the sub, away from where he suspected the next gas eruption would take place. On a CRT screen, the bottom-profiling sonar had drawn a digital picture of the surrounding seafloor, and it looked as though the tower had been erected in the middle of a series of hills. One of the hills had already vanished in a gas explosion, leaving the deep crater in its wake.

“C.W., what’s your status?” McKenzie asked.

“Stand by,” the young Californian called back. “Ah, I think I’m okay. I can do an emergency cut on my tether as long as Alan knows to come pick me up.”

“Temperature’s up three degrees,” Jervis warned.

Mercer keyed his mike. “C.W., when this deposit erupts, you’re going to be right above it. Are you sure you can hold on?”

“Yeah, I’ve locked the arms around a strut. I’m not going anywhere.”

Outside Bob’s cocoon of steel and composite materials, the water began to vibrate, and what little visibility they had vanished in a storm of fine silt. At first there was no sound, but quickly a bass tone built into a steady roar.

“Temp’s up another three.”

“Stay up-current of the tower and bring us to seven hundred feet,” Mercer ordered, banking that the plume of gas about to explode from the seafloor would drift away from them.

“Affirmative.”

With a suddenness no one expected, the ocean bottom vanished in a billowing smog that grew like the mushroom cloud of a nuclear detonation. The methane hydrate deposit, a massive pocket of frozen hydrocarbons, vaporized in a swelling cascade as warm water pumped from the top of the tower raised it to its boiling point. The leading edge of the gas raced for the surface, spinning in a maddened burst of energy like a giant tornado.

The sub was caught at the outer limit of the diffused eruption. Jervis had dumped ballast for the ascent and had the thrusters tilted down to help propel the craft toward the surface. Her rate of climb dropped once the frothy water engulfed the little sub.

“Damn,” Alan spat and increased thrust, mindful of the electrical charge remaining in the batteries.

“C.W., you’ve got to cut your tether,” Mercer shouted. “Jim, the deposit’s erupting. Get the Surveyor away as fast as you can. Head west against the current, otherwise you’ll be engulfed like the Smithback. Alan and I are trying to get into position if C.W. gets into trouble.”

“Once I’m off the tether, I lose communications.”

“I understand,” Mercer said. “We’re pushing Bob to reach your depth.” Outside the sub’s dome, the water surged and fizzed as though boiling.

“Rate of ascent down to fifty feet a minute and slowing,” Alan said.

“Can you dump more ballast?” asked Mercer, hating that for the duration of the dive he was nothing more than a passenger.

“Not if we want to hover at seven hundred to help C.W.”

“What about getting us farther from the main part of the gas plume?”

“If I change the vector on the thrusters, we’ll probably start falling. I’m afraid we’ll have to wait it out. Shit, we’re at neutral buoyancy.”

As hellish as the view from the sub was, what C.W. saw from inside the ADS was worse. The sub had been caught at the periphery of the eruption. He was right in the middle of it. So much methane had been released that at times he was engulfed in enormous sacs of the deadly gas. Stranded inside the bubbles, he could see water sluicing from his helmet like rain from a windshield. Then the bubble would pass and he’d be slammed again by the tremendous pressure of the sea. Several times he lost his footing and the suit’s metal claws that were his hands scraped against the tower strut.

At the surface, the scene was no better. McKenzie had relayed Mercer’s orders to the bridge with no time to spare. The helmsman had slammed the throttle handles to full ahead and twisted the ship with her dynamic positioning thrusters so she was pointed to the west, upstream from the tower. No sooner had she begun to move than the first hint of the gas reached the surface. It was just a mild disturbance of dirty water, a localized phenomenon that would have been overlooked as a downburst of wind disturbing the sea.

But then more and more methane broached. Seething geysers of water shot thirty, forty, fifty feet in the air. It was as though the sea was dissolving. A dive buoy that hadn’t been retrieved during the emergency maneuver sank away as the water lost density. The Surveyor became sluggish. Gas pockets were displacing the seawater she needed to remain afloat. She squatted low, with swells running just a few feet from her gleaming rails. More and more gas appeared. And then the steady eastward current began to carry it away. The ship found clean water and floated higher, the red stripe of her Plimsoll line clearly showing along her flanks.

Mercer’s quick warning had saved them from the same fate as the USS Smithback. For he and Alan, the dice were still rolling. And the plucky little submersible was falling deeper into the abyss.