The Mammoth Book of Perfect Crimes and Impossible Mysteries

Robert Weinberg (b. 1946) is a renowned collector and specialist in pulp magazines and pulp art who turned to writing, starting with a series featuring occult detective Alex Warner in The Devil’s Auction (1988). Lois Gresh (b. 1956) is a computer programmer and systems analyst. Their skills came together on the techno-thriller The Termination Node (1999). Their other collaborations include The Science of Superheroes (2002) and The Science of Supervillains (2004). Lois tells me that she once worked in a research establishment very similar to the one described here, but to say any more would spoil the story.

1

Once upon a time, after returning from the bank where I had the pleasure of making a six-figure deposit of the week’s earnings, I casually asked my boss, Penelope Peters, what special talent made her so incredibly successful. After all, Penelope, due to a genetic imperfection in her cells, suffered from extreme agoraphobia. She was unable to leave her home without suffering major panic attacks that left her a total mental and physical wreck. Yet, working from her office deep in the heart of Manhattan, she earned astonishing sums week after week solving problems that stumped the highest and the mightiest throughout the country, and sometime even the world. Having served as her assistant; chief bottle-washer; and eyes, ears, nose, and legs for the past five years, I had witnessed her genius so often I had become inured to her working miracles. I just wondered how.

“Brains and personality,” answered Penelope, with the barest twinkle in her green eyes. It was the punch line to one of the oldest and dumbest jokes around, and she loved using it.

“Yeah, right,” I countered, “save it for the newspapers. Tell me the truth. I’ve devoted the past five years of my life running errands, going to used book stores, attending board meetings, and catching crooks for you. It’s time I learned the secret handshake.” Then, to show that I wasn’t actually annoyed with her, I added, “Please.”

“Oh, well,” said Penelope, rising from behind her imposing ebony desk in the center of her office. “You won’t believe using the Magic 8-Ball, I assume?”

“Nope,” I replied. “Nor the ouija board explanation or the sack of old bones in the closet. I want the real stuff. So I can finally make my own way in the world, starting with a big advertisement on the internet: ‘Sean O’Brien, Investigations; formerly employed by the notorious Penelope Peters, World’s Premier Problem Solver. ‘“

Penelope frowned. “You’re not really thinking of leaving?” she asked. “It would take me years to train another assistant.”

“Decades,” I replied, with a grin. “It would take you decades. If not lifetimes.”

“Besides,” she said, “I haven’t sent you scouring used book stores for years now. I buy everything off the internet and have it delivered by Fed Ex.”

“There was that time I took the ferry to Hoboken-” I began, but she cut me off with the wave of a hand.

“Enough, enough,” she said. Penelope walked to the mahogany floor-to-ceiling bookcases that covered the left wall and laid one hand on the top of a well-read volume. “Everything I know I learned from studying this book. Read it, absorb it, and don’t forget it. That’s all you need to do to be just like me.”

That I doubted. I stand six foot two, weigh two hundred and forty pounds, and made it through college on a football scholarship. I have a degree in accounting, a detective’s badge, and a black belt in karate. I’m a fast talker, possess a near-photographic memory, and know how to follow instructions. My hair and eyes are black as coal, and nobody mistakes me for a movie star. Any resemblance between me and my boss is purely imaginary.

At five foot seven, 110 pounds, with green eyes and brown hair, Penelope Peters might have made it as a top fashion model if she lost fifteen or twenty pounds and could manage to leave her home on assignments. Since the second option was out of the question, she obviously saw no reason to consider the first. Not that I think she would have bothered. Penelope didn’t like taking orders from anyone, which was why she had set up her consulting business years before, when her agoraphobia was just starting to act up. In the time since, she’s become the problem solver that other problem solvers come to when they’re stumped. Her IQ number is off the charts, and her office is filled with rare trinkets and expensive gifts sent to her from satisfied clients throughout the world. Her brains didn’t come from any one book. But, I’m no dummy. I know what my boss is like. Besides, I was curious. I took the book.

“The Sign of Four by Sir Arthur Conan Doyle,” I read aloud. “Sherlock Holmes? Everything you know, you learned from Sherlock Holmes?”

“Elementary, my dear O’Brien,” said Penelope, with a smile.

“He’s not a real person. He’s a character in a book.”

“Real or not, he knew the secret to solving mysteries,” said Penelope. “Any sort of mysteries, be they problems with business to problems with murder.”

“Which is?” I asked.

Penelope removed The Sign of Four from my hands and flipped the book open to what had to be a familiar page. She read aloud,”… when you have eliminated the impossible, whatever remains, however improbable, must be the truth.”

“That’s it?” I said, somewhat doubtful. I must admit I wasn’t particularly impressed. Which explains, I suppose, why I’m the assistant and Penelope is the boss. “That’s all?”

“Nothing else,” said Penelope carefully sliding the book back into its place on the shelf. “A sharp mind, an attention for detail, and that sentence is all you need to solve the most perplexing puzzles ever encountered.”

“I find that hard to believe.”

“You’ll see,” said Penelope.

I did, of course, less than a month later, when Penelope solved the murder in Monkeyland.

2

Imagine if you will a four-story building in the shape of a square. Think of it built out of concrete and steel, with huge panoramic windows on each of the four levels, with a round information desk on the first floor and two large elevators in a concrete hub in the center of the square. In case of fire or any other sort of disaster, the elevators immediately lock into place in the shafts and can’t be used until the “all clear” alarm sounds.

Located in the corners of the square are four sets of emergency stairs. In case of an emergency, your only escape from an upper floor is down and out to the first floor. And, try as you may, there is no possible method of accessing any of the top three floors from the first.

Attached to each of the four sides of the square is a stubby concrete and steel rectangular wing, about twenty feet wide and thirty feet long. There are no windows or openings of any kind in these rectangles, and the concrete/steel walls are over two feet thick.

Located in each wing is a single laboratory. During the day, entrance to the labs is by a security card obtained at the desk. The cards are produced each morning by a random number generator and are only good for one day. They have to be carried at all times on the upper floors. If anyone without a card is detected by the many sensors located throughout the building, alarms immediately blare and the entire building complex locks down until the violator is caught. Each lab, due to the nature of the dangerous work being conducted within, has its own air supply and is powered by its own generator.

Still, Homeland Security deemed that these precautions were not enough. Which explains the huge movable concrete slabs on each side of the lab entrances.

When I first saw the slabs, my jaw dropped and I stood frozen for a minute in absolute awe. They were, without question, the biggest door jambs ever created. Each slab stood sixty feet high by ten feet across and was two feet deep. They were constructed from concrete laid over a metal frame of thin steel rods. Each massive slab rested on a motorized block of titanium steel. When the complex shut down for the night, the two slabs of concrete per laboratory slide together to meet and form an immovable door-one that couldn’t be opened by anyone less powerful than Samson or Hercules.

“You expecting an alien invasion?” I wondered aloud.

“Never hurts to be prepared,” said Captain Anthony Rackham, my escort for the afternoon. “Better safe than sorry when you’re dealing with plague and ebola bacteria.”

I shuddered, the full meaning of the complex’s nickname, The Slab, hitting home. The less time I spent in this building, the better. Hopefully, Penelope was going to solve this crime quickly.

“According to the briefing I received this morning,” I said, “researchers are permitted to remain in the labs overnight when working on a project?”

“Whenever they want,” said Rackham. “Just because we’re military doesn’t mean we don’t understand the needs of scientists. Each laboratory is equipped with a refrigerator, a microwave, a cot, and a bathroom complete with shower stall. Some of our top researchers spend weeks here without leaving their labs. They’re dedicated to the safety of our country.”

What Rackham considered dedication, I defined as obsessive behavior. But I was too polite to say so. Especially since the Captain was a good two inches taller than me and looked like he stepped out of a Conan the Barbarian movie. Not that he wasn’t all slick and polished, from his sharply pressed uniform to his shiny black shoes. Rackham had been assigned to me when I first checked into the complex a half-hour before. I still wasn’t sure if he was my escort or my guard. Not that it mattered. I was here strictly as a recording device for my boss.

The call had come in the middle of the night. A man was dead under mysterious circumstances. He’d been discovered in a locked and sealed concrete laboratory. No one was positive if it was a crime or not, but if it was, it needed to be solved immediately. The police and FBI were baffled. Contact Penelope Peters. Which meant I was off early the next morning to The Slab, a secret government complex fifty miles outside of Manhattan. Exactly in what direction that fifty miles was can’t be stated. Or so I was warned when given directions. And from the tone of the voice of the man on the phone, I knew he wasn’t kidding.

“Now that we’ve gone over the layout of the building,” I said, “how about showing me the scene of the crime.”

“You’re in charge,” said Rackham, waving me into one of the elevators. “It’s on the top floor.”

I noted with my usual efficiency that there were two cameras in the lift. The chances of someone making it upstairs undetected in this building were absolute zero.

“We don’t appreciate surprise visitors,” said Rackham, as we stepped out onto the fourth floor, in answer to my unspoken question. “The stuff stored in these labs could wipe out half the planet. Think of it as a terrorist supermarket.”

“Terrific,” I said. “You think Dr Schneider was killed by enemy agents?”

“I’m not a detective,” said Rackham, sounding slightly smug, the first emotion evident in his cold tones. “I have no idea who murdered Schneider, if anyone. He might have died from natural causes. Working in his lab would have given me a heart attack in a week.”

Rackham steered me across the floor to a lab sealed off with yellow police tape. A pair of marine guards holding rifles stood in front of the door into the wing. They snapped to attention as we approached. The captain pulled open the door to the laboratory and stepped aside.

“After you,” he said. The lights in the lab were on. They were always kept on. “The scene of the crime.”

I had no idea exactly what to expect, but whatever I might have imagined was immediately wiped away by what I saw upon entering the lab. What I saw and smell and heard.

“Welcome to Monkeyland,” said Rackham. The smugness in his voice was much more pronounced.

3

I should have been prepared, knowing that most of the work done in The Slab involved biological and chemical warfare, but I wasn’t. The entire back wall of the laboratory was covered from floor to ceiling with monkey cages. There must have been fifty metal pens in total though I never did spend the time to count them. Each cell, which is what they resembled most, held one small monkey-one small shrieking monkey, looking miserable in a boxed environment that barely gave it space to move. Each monkey wore a skull cap with electrodes protruding from it. With horror, I realized that researchers had removed the tops of the monkeys’ heads, stuck electrodes into their brains, and then topped the hideous surgery with what looked like party hats from hell. It was no wonder the monkeys were shrieking. The combined noise of dozens of monkeys was nerve shattering.

Adding to the beasts’ misery, the cages were arranged in rows, and since each pen had a solid metal floor to keep waste and food from dropping through the bars, the monkeys on the lower levels lived in a perpetual twilight. Those on the top row had the light, but because the fixtures were never shut off, they lived in perpetual sunshine. It was cruel torture either way.

Needless to say, the smell of half-eaten food, waste and urine didn’t improve my opinion of the lab. How anyone could conduct research in such a place was beyond me, but then again, I’m not a scientist. I turned to Rackham.

“Aren’t there laws about treating lab animals?” I said. “Are we really allowed to remove their skulls and literally torture them to death like this?”

“Yeah, we’re allowed. It’s how basic research is done: on animals. And it’s worse than what you’re seeing here. From what I hear, the scientists don’t let the animals eat or drink much, and they give food and water to the monkeys only if the monkeys cooperate during experiments. As for the lighting and cages and all that sort of thing, talk to the contractor who built this place for Homeland Security,” said Rackham. “They cut corners but got the job done fast. Friends in high places wanted results and if a few laws were broken, no one complained.”

Call me a naïve bumpkin. I should have realized that even during a time of war against terrorism or terror groups or radicals of any one cause or another, no-bid contracts and kickbacks never went out of style. And I should have realized that, just because the public doesn’t hear about the torture, doesn’t mean the torture isn’t going on.

“Look at the walls,” said Rackham, making no attempt to hide the anger and contempt in his voice. “There are cracks in the concrete due to water seepage and not enough support in the foundation. We’ve got mice in the basement and bats make their nests in the roof.”

“Bats?”

“Bats,” repeated Rackham. “Concrete walls are nice and dry, better than most caves. Drive by this complex at night and you’ll think you’re in Transylvania.”

Bats, plague, ebola germs, monkey brain surgeries, electrodes, and a building called The Slab. I was starting to feel like I had walked into a bad horror movie. I looked down at the floor. The outline of a body had been drawn in front of the monkey cages in blue chalk. It served as the last testament to Dr Carl Schneider.

The professor, his degree being in neurobiology, had been found the morning before when his assistant entered the lab. Schneider was slumped in front of the cages, with one door open and a monkey sitting on the nearby lab table chattering at the cold corpse. The researcher had been working on a hush-hush project involving monkeys and incurable motor function diseases, and he had spent the night in the lab. He had been alone when the slabs locked him in, and there was no record of the concrete blocks moving during the night. In effect, the scientist had been sealed inside a concrete box. Nobody came in, and nobody left.

All the physical evidence pointed to Schneider having just taken the beast out of the cage when a heart attack dropped him down. Both hands occupied with the scrambling monkey, the doctor never had a chance to grab for the phone and call for help. Everything suggested that Schneider had unfortunately suffered from sudden cardiac arrest and died in an instant.

There was no sign of a struggle. No wounds on his body, not even a scratch. The food and drink in the refrigerator had been tested and no poison detected. Gas was similarly ruled out, as polluting the air supply would have killed the monkeys in the lab as well as the doctor. Even the autopsy results pointed to a killer heart attack.

Why then the frantic call to Penelope Peters and my presence in the lab the next day? Because Dr Carl Schneider was thirty-one years old, was in near perfect health and, as far as anyone could tell, didn’t have a bad habit in the world. People like that don’t usually die from heart attacks.

“Any phone calls?” I asked, knowing the answer.

“Neither incoming or outgoing,” said Rackham. “Phone system works fine, in case you’re wondering. We checked it immediately after finding the body. He obviously died before he could contact the front desk. Not that it would have mattered. Once this place is sealed, it stays that way till morning.”

I walked around the lab, stared at the concrete walls, noted the tiny holes near the top. Big enough for a spider to crawl through, not much more. Attacked by a baby bat, I wondered, then dismissed the idea as beyond belief. A poisonous insect, perhaps? I was reading too many spy novels.

“Any chance the project he was working on caused his death?”

“No,” said Rackham. “Anything that would kill a man would kill all the monkeys in the lab. And they’re still alive.”

Definitely. The beasts screamed continually as I prowled around, trying to look like I knew what I was doing. Bright lights and screaming monkeys, it was enough to drive a man to drink. But murder? I couldn’t see how.

“Could he have been scared to death?” I asked, knowing how preposterous the idea sounded. “Was Schneider afraid of bugs? Maybe the janitor drew invisible paintings on the wall that could only be seen when the lights were turned off?”

Rackham snorted. “Dr Schneider was the most rational person I ever met. He had absolutely no imagination. Not the type to be scared by invisible ink. Besides, all of the maintenance crews are Marines with top-secret clearance. Plus the lights in this lab are never shut off.”

On the wall over the desk was an award paper in a gold frame. The paper indicated that Schneider had won a prestigious science award and $100,000 prize only last year. A framed photo of a skinny, pale white man with thinning brown hair dressed in a bathing suit standing next to an equally pale blond woman wearing a modest two-piece outfit rested alone on the desk. Some words were scribbled on the bottom of the picture.

“That Schneider?” I asked.

“The one and only,” said Rackham. “With Professor Mary Winfree, from the plague lab, down one floor.”

“To Carl, with lots of love, Mary.” It sounded like the possibility of a motive to me. Love, as the song said, changes everything. “Let’s go visit Professor Winfree.”

4

If Schneider’s lab was Monkeyland, then Winfree’s domain was obviously Mouseville. The lady professor’s laboratory was one floor down from the murder scene and was arranged in much the same layout as the room above. Cages to the rear, scientific equipment of all sorts to the left, minimal living comforts to the right. When we entered the lab, Winfree was examining a slide under a microscope while in the rear two assistants in white coats were feeding the mice. The professor peered at us with wide blue-gray eyes. “Can I help you gentlemen? This is a restricted area.”

“This whole building is a restricted area, Professor,” said Rackham. “We all know that. I’m Captain Rackham, and this is Mr O’Brien. We’re investigating Dr Schneider’s death.”

“Oh, yes,” said Winfree, a faint blush rising in her cheeks. “Carl’s death. So unfortunate. Investigating? I don’t understand. I thought he died of natural causes?”

“A heart attack at thirty-one?” I asked. “Rather young for heart disease, don’t you think?”

Winfree stood up, her fingers fluttering. She looked like she was ready to fly away. “I – I never considered that. But why question me? Carl and I weren’t close. The last time I spoke with him was a week ago.”

“There was a photo on his desk,” I said. “Signed by you, with lots of love?”

The professor giggled, a high-pitched sound that startled the mice in the rear of the lab, which began squeaking. “A brief flirtation at the beach last summer. A few weeks in the sun. Surely not a reason for foul play. Carl and I were still fond of each other. Sometimes we even talked about going on another trip, but it never amounted to much. That’s because neither of us was willing to abandon our first love.”

“First love?” I asked.

“Our work, of course.”

“Right,” I replied. “Anyone you suspect other than terrorists or PETA activists who would have wanted to harm Dr Schneider? Angry relatives, old girlfriends?”

“No-o-o,” said Winfree, drawing the word out the length of a sentence. “Carl didn’t associate with people outside of the complex. None of us do. We’re devoted to our work. It’s our life.”

I nodded. Obsessed. Great for the country, bad for a murder investigation.

“I wasn’t even here the other night,” continued Winfree. “I was giving a lecture at the university. You should ask Otto if anything strange happened. He’s always around.”

We left Professor Winfree after a few more questions. If she was guilty of murdering Schneider, then I was a monkey’s uncle. Though, I’ve been wrong before. Plenty of times.

“Who’s Otto?” I asked.

“First floor,” said Rackham. “Otto Klax, Professor of Neurobiology, the man in charge of our MEMS program.” Rackham sighed. “Another genius with underdeveloped social skills. At least he doesn’t work with lab animals. Not enough room in his lab for anything other than him and his ego.”

MEMS referred to mechanical components on the micrometer size and included 3D lithographic features of various geometries. They were made using planar processing similar to semiconductor processes such as surface micromachining. Devices using them ranged in size from a millionth of a meter to a thousandth of a meter. Too small to even imagine, yet they were the hottest item in military circles. I noted that both Schneider and Klax were neurobiologists, yet while Schneider concentrated on the brain, Klax’s focus was on MEMS. “Why would a neurobiologist be working with MEMS?” I asked Rackham.

He shrugged. “More sadistic torture of innocent animals, I suppose. They build tiny electrical and mechanical devices that they implant into animal brains. Klax builds the devices, Schneider uses them. Klax does a lot of the hard work, Schneider gets the glory. Not that I’d call an award for torturing animals to their deaths, glory.”

I had to agree with Rackham. Even the salary of a Klax or Schneider was nothing more than blood money.

If Otto Klax had even the slightest trace of personality, he could have played a mad scientist in a horror movie. He definitely looked the part, standing six foot six and weighing no more than a hundred and fifty pounds. Thin enough that if he turned sideways he didn’t leave a shadow. Jet black hair, a thin moustache, and tiny black eyes that darted around the room, never making direct contact with anyone. He spoke softly and in a rush, making his speech almost incomprehensible.

“What do you want with me?” he asked, seconds after we introduced ourselves. “I’m much too busy for anything you want to talk about anyway. Much, much too busy for idle chit-chat. Not enough time in the day as it is. What do you want, why are you bothering me?”

“Dr Schneider died in his lab the night before last,” said Rackham. “Professor Winfree suggested we ask you if anything strange happened in the complex that evening.”

“Mary said that?” said Klax. “I don’t know why she would think so. I was in my office working, as usual. All night, every night. Locked in here like a rat in a trap, no way out, nothing to do but wait till morning. If anything weird took place, I wouldn’t know. Not me, locked behind these concrete slabs.

“Besides,” continued Klax, “Schneider worked with monkeys and I hate monkeys. Dirty rotten little beasts. There’s nothing for me to gain from Schneider’s death. Only one who benefits is Arronds, his assistant. Talk to him, he’s the one with a motive. Now, get out. I have machines to build, reports to write. Get out, get out. Stop wasting my time.”

Marvin Arronds had waved good night to Schneider when the slabs closed and locked, and had found the professor’s body in the center of the lab the next morning. According to the few locked-room mystery stories I’ve read, that made him the most likely candidate for murdering his boss. Unfortunately, none of those stories offered any explanation about how Arronds could have managed the task with no one the wiser. Nor did they explain the two Marine guards who had also seen Schneider alive when the slabs had locked shut.

“Me? Kill the professor?” said Arronds, a short, rotund man, with a shaved head and a voice that boomed like a megaphone. Necessary to be heard over the monkeys, I guessed. “That’s the craziest thing I’ve ever heard. Sure, I worked in the laboratory, but Dr Schneider was the genius. Besides, the professor was my friend. Sure, he was a nerd, but that was okay. Everybody liked him.”

“Dr Klax suggested that-” I began.

“Dr Klax is nuts,” said Arronds, sounding furious. He pointed a finger the size of a sausage at my face. “Guy’s a paranoid fruitcake. Thinks everyone is out to steal his ideas.”

Five minutes of questioning Arronds further convinced me that, if he had invented a unique method of murder, it was the first thing he’d ever discovered in his life. He was strictly a bottle washer with a degree in biology. More to the point, he genuinely seemed to have liked Schneider. I mentally crossed him off my list of suspects, which left me zero for three.

“You want to interview the professors in the east wing next?” asked Rackham when I was finished with Arronds.

“Sure, why not,” I replied. I had a feeling this was going to be a long day – a very long day.

5

I arrived home around nine that night. Penelope was sitting in the TV room, watching a rerun of Law and Order. She took one look at the sour expression on my face and ordered me to the kitchen. “Julian made shrimp for dinner. There should be some leftovers in the refrigerator. Eat and drink, then report.”

It took me nearly two hours to describe my day. During the entire recital, Penelope only interrupted once. “Bats? Did you actually see bats?”

“Flying over the rooftop when I left,” I assured her. “Little ones, but definitely not birds. Bats.”

Penelope nodded then settled back and let me drone away. I did my usual fine job of imitating a video recorder, describing in great detail everything I had seen, heard, and smelled the entire time I had been away. By the time I finished, she was having difficulty covering her yawns.

“I know, it’s not very exciting stuff,” I said, “but if anyone committed a crime in that place, I’ve no idea how.”

“That’s because you’ve forgotten your Sherlock Holmes,” said Penelope, rising from behind the desk. “I’m going to bed. I suggest you do the same. Tomorrow, we’ll need to be at our best for the seance.”

“Seance? We’re having a seance?”

“Of course,” said Penelope. “What better way to identify a murderer?”

What Penelope Peters wants, Penelope Peters gets. Especially when she’s working for the government and they’re anxious for results. Wearing a black tuxedo and feeling pretty much the idiot, I answered the doorbell the next evening at 8 p.m. Standing on the steps were Captain Rackham, Mary Winfree, Otto Klax, and Marvin Arronds. Backing them up were two Marines. Our guests had arrived.

As instructed, I ushered them into the parlor, which Julian and I had earlier arranged per the boss’s instructions. A small round table sat in the middle of the room covered by a black cloth. In the center of the table was a crystal ball I had rented earlier in the day from a Manhattan theater props store. Six wood chairs circled the table. I arranged everyone exactly as Penelope wished. First came Mary Winfree, then Rackham, then Otto Klax, then me, then Marvin Arronds. The blank chair was for my boss.

Penelope entered in a swirl of black silk. She looked very much the gypsy fortune-teller with her hair up in a knot and several strings of costume jewelry around her neck. “Thank you for attending tonight’s service,” she said, nodding to everyone. “Would you please be seated.”

“This is nonsense,” said Klax, “pure nonsense,” but he sat down. No one else said anything, though they all looked puzzled.

“Now, please form a circle by holding hands,” commanded Penelope. “That includes you, Dr Klax.”

“This is a waste of time,” said Klax, pulling his hands out of his coat pockets and linking his cold fingers with Rackham’s on one side and mine on the other. “I should be back at my lab, working.”

“Working?” said Penelope. “Or planning another murder?”

“What are you babbling about?” said Klax, trying to wrench his hands free. Not that he could. Which had been the point of this entire charade, making sure Klax couldn’t use the miniature control unit the Marine guards later found in his left pocket.

“I never touched Schneider,” declared Klax. “I was in my lab all night.”

“Yes, you were,” said Penelope. “Safe and secure in your laboratory while your MEMS robots, programmed by you, climbed up through the cracks in the concrete walls and killed Professor Schneider.”

“Say what?” I was so surprised I almost let go of Klax’s cold fingers. Almost.

“MEMS robots are so small they can fit into spaces only a few thousandths of an inch wide,” said Penelope. “If artificially intelligent, they can be programmed to assemble themselves into bigger machines once they reach a specific destination. For example, they can go through small cracks between a wall and ceiling, then assemble into a larger flying robot. They can be programmed to seek and attack a specific target: in this case, Dr Schneider. Klax’s devices carried a payload of hydrogen cyanide with them and loaded it into the stinger of a mechanical mosquito.”

“Cyanide gas kills people almost instantly,” I said, Penelope’s words starting to sink in. “The results mimic a heart attack, and all traces dissolve into the body within hours. But how could a mosquito deliver enough gas to kill Schneider?”

“It was all a matter of waiting for the proper moment,” said Penelope. “Klax knew that sometime during the night Schneider would lift one of the monkeys out of its cage. With both his hands occupied, the professor couldn’t stop the attack that killed him.”

“The mechanical mosquito-”

“- flew into Dr Schneider’s nose and squirted the hydrogen cyanide into his nasal passage,” said Penelope, finishing my thought. “A small dose inhaled at such close range would kill in seconds.”

“But why?” said Mary Winfree, her questions directed at Klax, not us. “Why on earth would you want to kill Carl?”

Klax rose from the table, and towering six foot six, and having wrenched his hands free, lifted both fists in the air. “How can you even ask that question, Mary? I did all the work. He won all the awards. He got the money, the fame, the glory. And because of all that, he got you.”

“Me?” she said. “What do I have to do with this?”

“He lusted after you, and I couldn’t allow it,” said Klax, a very strange note creeping into his voice. “I wanted you, and you never even looked my way, Mary. My robot spies heard him talking to you on the phone last week. Trying to seduce you. Take you on another trip. That’s when I decided he had to die. He couldn’t have the awards that were supposed to be mine, the money and honors that were supposed to be mine, and now you, too! I just couldn’t allow it!”

“You,” said Mary Winfree, “are a very sick and misguided man. You’re crazy, Klax!”

And so it was jealousy, after all, that killed Dr Schneider. Not a monkey. Not a bat. And to my surprise, something deadly was able to penetrate the fortress called The Slab. Where nothing goes in and nothing comes out, murder took place.

The Marines found a fistful of tiny machines in Klax’s right pocket, a miniature control device in the other. Proof positive that he had used such micro-machines for murder and a grim reminder that Penelope’s subterfuge had saved anyone else from being killed.

“I had Captain Rackham bring the two of you with Klax tonight so he wouldn’t guess we specifically suspected him,” explained Penelope to Arronds and Winfree, once the Marines had left with their prisoner. “I also thought, since you were Dr Schneider’s friends, you would want to help capture his murderer.”

“An amazing deduction,” said Arronds. “How did you figure out it was Klax?”

“She asked Sherlock Holmes,” I answered.