Poul Anderson

"If you would build a tower, sit
down first and count the cost, to see
if you have enough to finish it." ...
The price may be much too high.

[Transcriber's Note: This etext was produced from
Worlds of If Science Fiction, June 1956.
Extensive research did not uncover any evidence that
the U.S. copyright on this publication was renewed.]

"The chickens got out of the coop and flew away three hundred years ago," said Barwell. "Now they're coming home to roost."

He hiccoughed. His finger wobbled to the dial and clicked off another whisky. The machine pondered the matter and flashed an apologetic sign: Please deposit your money.

"Oh, damn," said Barwell. "I'm broke."

Radek shrugged and gave the slot a two-credit piece. It slid the whisky out on a tray with his change. He stuck the coins in his pouch and took another careful sip of beer.

Barwell grabbed the whisky glass like a drowning man. He would drown, thought Radek, if he sloshed much more into his stomach.

There was an Asian whine to the music drifting past the curtains into the booth. Radek could hear the talk and laughter well enough to catch their raucous overtones. Somebody swore as dice rattled wrong for him. Somebody else shouted coarse good wishes as his friend took a hostess upstairs.

He wondered why vice was always so cheerless when you went into a place and paid for it.

"I am going to get drunk tonight," announced Barwell. "I am going to get so high in the stony sky you'll need radar to find me. Then I shall raise the red flag of revolution."

"And tomorrow?" asked Radek quietly.

Barwell grimaced. "Don't ask me about tomorrow. Tomorrow I will be among the great leisure class—to hell with euphemisms—the unemployed. Nothing I can do that some goddam machine can't do quicker and better. So a benevolent state will feed me and clothe me and house me and give me a little spending money to have fun on. This is known as citizen's credit. They used to call it a dole. Tomorrow I shall have to be more systematic about the revolution—join the League or something."

"The trouble with you," Radek needled him, "is that you can't adapt. Technology has made the labor of most people, except the first-rank creative genius, unnecessary. This leaves the majority with a void of years to fill somehow—a sense of uprootedness and lost self-respect—which is rather horrible. And in any case, they don't like to think in scientific terms ... it doesn't come natural to the average man."

Barwell gave him a bleary stare out of a flushed, sagging face. "I s'pose you're one of the geniuses," he said. "You got work."

"I'm adaptable," said Radek. He was a slim youngish man with dark hair and sharp features. "I'm not greatly gifted, but I found a niche for myself. Newsman. I do legwork for a major commentator. Between times, I'm writing a book—my own analysis of contemporary historical trends. It won't be anything startling, but it may help a few people think more clearly and adjust themselves."

"And so you like this rotten Solar Union?" Barwell's tone became aggressive.

"Not everything about it no. So there is a wave of antiscientific reaction, all over Earth. Science is being made the scapegoat for all our troubles. But like it or not, you fellows will have to accept the fact that there are too many people and too few resources for us to survive without technology."

"Some technology, sure," admitted Barwell. He took a ferocious swig from his glass. "Not this hell-born stuff we've been monkeying around with. I tell you, the chickens have finally come home to roost."

Radek was intrigued by the archaic expression. Barwell was no moron: he'd been a correlative clerk at the Institute for several years, not a position for fools. He had read, actually read books, and thought about them.

And today he had been fired. Radek chanced across him drinking out a vast resentment and attached himself like a reverse lamprey—buying most of the liquor. There might be a story in it, somewhere. There might be a lead to what the Institute was doing.

Radek was not antiscientific, but neither did he make gods out of people with technical degrees. The Institute must be up to something unpleasant ... otherwise, why all the mystery? If the facts weren't uncovered in time, if whatever they were brewing came to a head, it could touch off the final convulsion of lynch law.

Barwell leaned forward, his finger wagged. "Three hundred years now. I think it's three hundred years since X-rays came in. Damn scientists, fooling around with X-rays, atomic energy, radioactives ... sure, safe levels, established tolerances, but what about the long-range effects? What about cumulative genetic effects? Those chickens are coming home at last."

"No use blaming our ancestors," said Radek. "Be rather pointless to go dance on their graves, wouldn't it?"

Barwell moved closer to Radek. His breath was powerful with whisky. "But are they in those graves?" he whispered.

"Huh?"

"Look. Been known for a long time, ever since first atomic energy work ... heavy but nonlethal doses of radiation shorten lifespan. You grow old faster if you get a strong dose. Why d'you think with all our medicines we're not two, three hundred years old? Background count's gone up, that's why! Radioactives in the air, in the sea, buried under the ground. Gamma rays, not entirely absorbed by shielding. Sure, sure, they tell us the level is still harmless. But it's more than the level in nature by a good big factor—two or three."

Radek sipped his beer. He'd been drinking slowly, and the beer had gotten warmer than he liked, but he needed a clear head. "That's common knowledge," he stated. "The lifespan hasn't been shortened any, either."

"Because of more medicines ... more ways to help cells patch up radiation damage. All but worst radiation sickness been curable for a long time." Barwell waved his hand expansively. "They knew, even back then," he mumbled. "If radiation shortens life, radiation sickness cures ought to prolong it. Huh? Reas'nable? Only the goddam scientists ... population problem ... social stasis if ever'body lived for centuries ... kept it secret. Easy t' do. Change y'r name and face ever' ten, twen'y years—keep to y'rself, don't make friends among the short-lived, you might see 'em grow old and die, might start feelin' sorry for 'em an' that would never do, would it—?"

Coldness tingled along Radek's spine. He lifted his mug and pretended to drink. Over the rim, his eyes stayed on Barwell.

"Tha's why they fired me. I know. I know. I got ears. I overheard things. I read ... notes not inten'ed for me. They fired me. 'S a wonder they didn' murder me." Barwell shuddered and peered at the curtains, as if trying to look through them. "Or d'y' think—maybe—"

"No," said Radek. "I don't. Let's stick to the facts. I take it you found mention of work on—shall we say—increasing the lifespan. Perhaps a mention of successes with rats and guinea pigs. Right? So what's wrong with that? They wouldn't want to announce anything till they were sure, or the hysteria—"

Barwell smiled with an irritating air of omniscience. "More'n that, friend. More'n that. Lots more."

"Well, what?"

Barwell peered about him with exaggerated caution. "One thing I found in files ... plans of whole buildin's an' groun's—great, great big room, lotsa rooms, way way underground. Secret. Only th' kitchen was makin' food an' sendin' it down there—human food. Food for people I never saw, people who never came up—" Barwell buried his face in his hands. "Don' feel so good. Whirlin'—"

Radek eased his head to the table. Out like a spent credit. The newsman left the booth and addressed a bouncer. "Chap in there has had it."

"Uh-huh. Want me to help you get him to your boat?"

"No. I hardly know him." A bill exchanged hands. "Put him in your dossroom to sleep it off, and give him breakfast with my compliments. I'm going out for some fresh air."

The rec house stood on a Minnesota bluff, overlooking the Mississippi River. Beyond its racket and multi-colored glare, there was darkness and wooded silence. Here and there the lights of a few isolated houses gleamed. The river slid by, talking, ruffled with moonlight. Luna was nearly full; squinting into her cold ashen face, Radek could just see the tiny spark of a city. Stars were strewn carelessly over heaven, he recognized the ember that was Mars.

Perhaps he ought to emigrate. Mars, Venus, even Luna ... there was more hope on them than Earth had. No mechanical packaged cheer: people had work to do, and in their spare time made their own pleasures. No civilization cracking at the seams because it could not assimilate the technology it must have; out in space, men knew very well that science had carried them to their homes and made those homes fit to dwell on.

Radek strolled across the parking lot and found his airboat. He paused by its iridescent teardrop to start a cigaret.

Suppose the Institute of Human Biology was more than it claimed to be, more than a set of homes and laboratories where congenial minds could live and do research. It published discoveries of value—but how much did it not publish? Its personnel kept pretty aloof from the rest of the world, not unnatural in this day of growing estrangement between science and public ... but did they have a deeper reason than that?

Suppose they did keep immortals in those underground rooms.

A scientist was not ordinarily a good political technician. But he might think he could be. He might react emotionally against a public beginning to throw stones at his house and consider taking the reins ... for the people's own good, of course. A lot of misery had been caused the human race for its own alleged good.

Or if the scientist knew how to live forever, he might not think Joe Smith or Carlos IbÁÑez or Wang Yuan or Johannes Umfanduma good enough to share immortality with him.

Radek took a long breath. The night air felt fresh and alive in his lungs after the tavern staleness.

He was not currently married, but there was a girl with whom he was thinking seriously of making a permanent contract. He had friends, not lucent razor minds but decent, unassuming, kindly people, brave with man's old quiet bravery in the face of death and ruin and the petty tragedies of everyday. He liked beer and steaks, fishing and tennis, good music and a good book and the exhilarating strain of his work. He liked to live.

Maybe a system for becoming immortal, or at least living many centuries, was not desirable for the race. But only the whole race had authority to make that decision.

Radek smiled at himself, twistedly, and threw the cigaret away and got into the boat. Its engine murmured, sucking 'cast power; the riding lights snapped on automatically and he lifted into the sky. It was not much of a lead he had, but it was as good as he was ever likely to get.

He set the autopilot for southwest Colorado and opened the jets wide. The night whistled darkly around his cabin. Against wan stars, he made out the lamps of other boats, flitting across the world and somehow intensifying the loneliness.

Work to do. He called the main office in Dallas Unit and taped a statement of what he knew and what he planned. Then he dialed the nearest library and asked the robot for information on the Institute of Human Biology.

There wasn't a great deal of value to him. It had been in existence for about 250 years, more or less concurrently with the Psychotechnic Institute and for quite a while affiliated with that organization. During the Humanist troubles, when the Psychotechs were booted out of government on Earth and their files ransacked, it had dissociated itself from them and carried on unobtrusively. (How much of their secret records had it taken along?) Since the Restoration, it had grown, drawing in many prominent researchers and making discoveries of high value to medicine and bio-engineering. The current director was Dr. Marcus Lang, formerly of New Harvard, the University of Luna, and—No matter. He'd been running the show for eight years, after his predecessor's death.

Or had Tokogama really died?

He couldn't be identical with Lang—he had been a short Japanese and Lang was a tall Negro, too big a jump for any surgeon. Not to mention their simultaneous careers. But how far back could you trace Lang before he became fakeable records of birth and schooling? What young fellow named Yamatsu or Hideki was now polishing glass in the labs and slated to become the next director?

How fantastic could you get on how little evidence?

Radek let the text fade from the screen and sat puffing another cigaret. It was a while before he demanded references on the biology of the aging process.

That was tough sledding. He couldn't follow the mathematics or the chemistry very far. No good popularizations were available. But a newsman got an ability to winnow what he learned. Radek didn't have to take notes, he'd been through a mind-training course; after an hour or so, he sat back and reviewed what he had gotten.

The living organism was a small island of low entropy in a universe tending constantly toward gigantic disorder. It maintained itself through an intricate set of hemostatic mechanisms. The serious disruption of any of these brought the life-processes to a halt. Shock, disease, the bullet in the lungs or the ax in the brain—death.

But hundreds of thousands of autopsies had never given an honest verdict of "death from old age." It was always something else, cancer, heart failure, sickness, stroke ... age was at most a contributing cause, decreasing resistance to injury and power to recover from it.

One by one, the individual causes had been licked. Bacteria and protozoa and viruses were slaughtered in the body. Cancers were selectively poisoned. Cholesterol was dissolved out of the arteries. Surgery patched up damaged organs, and the new regeneration techniques replaced what had been lost ... even nervous tissue. Offhand, there was no more reason to die, unless you met murder or an accident.

But people still grew old. The process wasn't as hideous as it had been. You needn't shuffle in arthritic feebleness. Your mind was clear, your skin wrinkled slowly. Centenarians were not uncommon these days. But very few reached 150. Nobody reached 200. Imperceptibly, the fires burned low ... vitality was diminished, strength faded, hair whitened, eyes dimmed. The body responded less and less well to regenerative treatment. Finally it did not respond at all. You got so weak that some small thing you and your doctor could have laughed at in your youth, took you away.

You still grew old. And because you grew old, you still died.

The unicellular organism did not age. But "age" was a meaningless word in that particular case. A man could be immortal via his germ cells. The micro-organism could too, but it gave the only cell it had. Personal immortality was denied to both man and microbe.

Could sheer mechanical wear and tear be the reason for the decline known as old age? Probably not. The natural regenerative powers of life were better than that. And observations made in free fall, where strain was minimized, indicated that while null-gravity had an alleviating effect, it was no key to living forever.

Something in the chemistry and physics of the cells themselves, then. They did tend to accumulate heavy water—that had been known for a long time. Hard to see how that could kill you ... the percentage increase in a lifetime was so small. It might be a partial answer. You might grow old more slowly if you drank only water made of pure isotopes. But you wouldn't be immortal.

Radek shrugged. He was getting near the end of his trip. Let the Institute people answer his questions.

The Four Corners country is so named because four of the old American states met there, back when they were still significant political units. For a while, in the 20th century, it was overrun with uranium hunters, who made small impression on its tilted emptiness. It was still a favorite vacation area, and the resorts were lost in that great huddle of mountains and desert. You could have a lot of privacy here.

Gliding down over the moon-ghostly Pueblo ruins of Mesa Verde, Radek peered through the windscreen. There, ahead. Lights glowed around the walls, spread across half a mesa. Inside them was a parkscape of trees, lawns, gardens, arbors, cottage units ... the Institute housed its people well. There were four large buildings at the center, and Radek noted gratefully that several windows were still shining in them. Not that he had any compunctions about getting the great Dr. Lang out of bed, but—

He ignored the public landing field outside the walls and set his boat down in the paved courtyard.

As he climbed out, half a dozen guards came running. They were husky men in blue uniforms, armed with stunners, and the dim light showed faces hinting they wouldn't be sorry to feed him a beam. Radek dropped to the ground, folded his arms, and waited. The breath from his nose was frosty under the moon.

"What the hell do you want?"

The nearest guard pulled up in front of him and laid a hand on his shock gun. "Who the devil are you? Don't you know this is private property? What's the big idea, anyway?"

"Take it easy," advised Radek. "I have to see Dr. Lang at once. Emergency."

"You didn't call for an appointment, did you?"

"No, I didn't."

"All right, then—"

"I didn't think he'd care to have me give my reasons over a radio. This is confidential and urgent."

The men hesitated, uncertain before such an outrageous violation of all civilized canons. "I dunno, friend ... he's busy ... if you want to see Dr. McCormick—"

"Dr. Lang. Ask him if I may. Tell him I have news about his longevity process."

"His what?"

Radek spelled it out and watched the man go. Another one made some ungracious remark and frisked him with needless ostentation. A third was more urbane: "Sorry to do this, but you understand we've got important work going on. Can't have just anybody busting in."

"Sure, that's all right." Radek shivered in the thin chill air and pulled his cloak tighter about him.

"Viruses and stuff around. If any of that got loose—You understand."

Well, it wasn't a bad cover-up. None of these fellows looked very bright. IQ treatments could do only so much, thereafter you got down to the limitations of basic and unalterable brain microstructure. And even among the more intellectual workers ... how many Barwells were there, handling semi-routine tasks but not permitted to know what really went on under their feet? Radek had a brief irrational wish that he'd worn boots instead of sandals.

The first guard returned. "He'll see you," he grunted. "And you better make it good, because he's one mad doctor."

Radek nodded and followed two of the men. The nearest of the large square buildings seemed given over to offices. He was led inside, down a short length of glow-lit corridor, and halted while the scanner on a door marked, LANG, DIRECTOR observed him.

"He's clean, boss," said one of the escort.

"All right," said the annunciator. "Let him in. But you two stay just outside."

It was a spacious office, but austerely furnished. A telewindow reflected green larches and a sun-spattered waterfall, somewhere on the other side of the planet. Lang sat alone behind the desk, his hands engaged with some papers that looked like technical reports. He was a big, heavy-shouldered man, his hair gray, his chocolate face middle-aged and tired.

He did not rise. "Well?" he snapped.

"My name is Arnold Radek. I'm a news service operator ... here's my card, if you wish to see it."

"Pharaoh had it easy," said Lang in a chill voice. "Moses only called the seven plagues down on him. I have to deal with your sort."

Radek placed his fingertips on the desk and leaned forward. He found it unexpectedly hard not to be stared down by the other. "I know very well I've laid myself open to a lawsuit by coming in as I did," he stated. "Possibly, when I'm through, I'll be open to murder."

"Are you feeling well?" There was more contempt than concern in the deep tone.

"Let me say first off, I believe I have information about a certain project of yours. One you badly want to keep a secret. I've taped a record at my office of what I know and where I'm going. If I don't get back before 1000 hours, Central Time, and wipe that tape, it'll be heard by the secretary."

Lang took an exasperated breath. His fingernails whitened on the sheets he still held. "Do you honestly think we would be so ... I won't say unscrupulous ... so stupid as to use violence?"

"No," said Radek. "Of course not. All I want is a few straight answers. I know you're quite able to lead me up the garden path, feed me some line of pap and hustle me out again—but I won't stand for that. I mentioned my tape only to convince you that I'm in earnest."

"You're not drunk," murmured Lang. "But there are a lot of people running loose who ought to be in a mental hospital."

"I know." Radek sat down without waiting for an invitation. "Anti-scientific fanatics. I'm not one of them. You know Darrell Burkhardt's news commentaries? I supply a lot of his data and interpretations. He's one of the leading friends of genuine science, one of the few you have left." Radek gestured at the card on the desk. "Read it, right there."

Lang picked the card up and glanced at the lettering and tossed it back. "Very well. That's still no excuse for breaking in like this. You—"

"It can't wait," interrupted Radek. "There are a lot of lives at stake. Every minute we sit here, there are perhaps a million people dying, perhaps more; I haven't the figures. And everyone else is dying all the time, millimeter by millimeter, we're all born dying. Every minute you hold back the cure for old age, you murder a million human beings."

"This is the most fantastic—"

"Let me finish! I get around. And I'm trained to look a little bit more closely at the facts everybody knows, the ordinary commonplace facts we take for granted and never think to inquire about because they are so ordinary. I've wondered about the Institute for a long time. Tonight I talked at great length with a fellow named Barwell ... remember him? A clerk here. You fired him this morning for being too nosy. He had a lot to say."

"Hm." Lang sat quiet for a while. He didn't rattle easily—he couldn't be snowed under by fast, aggressive talk. While Radek spat out what clues he had, Lang calmly reached into a drawer and got out an old-fashioned briar pipe, stuffed it and lit it.

"So what do you want?" he asked when Radek paused for breath.

"The truth, damn it!"

"There are privacy laws. It was established long ago that a citizen is entitled to privacy if he does nothing against the common weal—"

"And you are! You're like a man who stands on a river bank and has a lifebelt and won't throw it to a man drowning in the river."

Lang sighed. "I won't deny we're working on longevity," he answered. "Obviously we are. The problem interests biologists throughout the Solar System. But we aren't publicizing our findings as yet for a very good reason. You know how people jump to conclusions. Can you imagine the hysteria that would arise in this already unstable culture if there seemed to be even a prospect of immortality? You yourself are a prime case ... on the most tenuous basis of rumor and hypothesis, you've decided that we have found a vaccine against old age and are hoarding it. You come bursting in here in the middle of the night, demanding to be made immortal immediately if not sooner. And you're comparatively civilized ... there are enough lunatics who'd come here with guns and start shooting up the place."

Radek smiled bleakly. "Of course. I know that. And you ought to know the outfit I work for is reputable. If you have a good lead on the problem, but haven't solved it yet, you can trust us not to make that fact public."

"All right." Lang mustered an answering smile, oddly warm and charming. "I don't mind telling you, then, that we do have some promising preliminary results—but, and this is the catch, we estimate it will take at least a century to get anywhere. Biochemistry is an inconceivably complex subject."

"What sort of results are they?"

"It's highly technical. Has to do with enzymes. You may know that enzymes are the major device through which the genes govern the organism all through life. At a certain point, for instance, the genes order the body to go through the changes involved in puberty. At another point, they order that gradual breakdown we know as aging."

"In other words," said Radek slowly, "the body has a built-in suicide mechanism?"

"Well ... if you want to put it that way—"

"I don't believe a word of it. It makes a lot more sense to imagine that there's something which causes the breakdown—a virus, maybe—and the body fights it off as long as possible but at last it gets the upper hand. The whole key to evolution is the need to survive. I can't see life evolving its own anti-survival factor."

"But nature doesn't care about the individual, friend Radek. Only about the species. And the species with a rapid turnover of individuals can evolve faster, become more effective—"

"Then why does man, the fastest-evolving metazoan of all, have one of the longest lifespans? He does, you know ... among mammals, at any rate. Seems to me our bodies must be all-around better than average, better able to fight off the death virus. Fish live a longer time, sure—and maybe in the water they aren't so exposed to the disease. May flies are short-lived; have they simply adapted their life cycle to the existence of the virus?"

Lang frowned. "You appear to have studied this subject enough to have some mistaken ideas about it. I can't argue with a man who insists on protecting his cherished irrationalities with fancy verbalisms."

"And you appear to think fast on your feet, Dr. Lang." Radek laughed. "Maybe not fast enough. But I'm not being paranoid about this. You can convince me."

"How?"

"Show me. Take me into those underground rooms and show me what you actually have."

"I'm afraid that's impos—"

"All right." Radek stood up. "I hate to do this, but a man must either earn a living or go on the public freeloading roll ... which I don't want to do. The facts and conjectures I already have will make an interesting story."

Lang rose too, his eyes widening. "You can't prove anything!"

"Of course I can't. You're sitting on all the proof."

"But the public reaction! God in Heaven, man, those people can't think!"

"No ... they can't, can they?" He moved toward the door. "Goodnight."

Radek's muscles were taut. In spite of everything that had been said, a person hounded to desperation could still do murder.

There was a great quietness as he neared the door. Then Lang spoke. The voice was defeated, and when Radek looked back it was an old man who stood behind the desk.

"You win. Come along with me."

They went down an empty hall, after dismissing the guards, and took an elevator below ground. Neither of them said anything. Somehow, the sag of Lang's shoulders was a gnawing in Radek's conscience.

When they emerged, it was to transfer past a sentry, where Lang gave a password and okayed his companion, to another elevator which purred them still deeper.

"I—" The newsman cleared his throat, awkwardly. "I repeat what I implied earlier. I'm here mostly as a citizen interested in the public welfare ... which includes my own, of course, and my family's if I ever have one. If you can show me valid reasons for not breaking this story, I won't. I'll even let you hypnocondition me against doing it, voluntarily or otherwise."

"Thanks," said the director. His mouth curved upward, but it was a shaken smile. "That's decent of you, and we'll accept ... I think you'll agree with our policy. What worries me is the rest of the world. If you could find out as much as you did—"

Radek's heart jumped between his ribs. "Then you do have immortality!"

"Yes. But I'm not immortal. None of our personnel are, except—Here we are."

There was a hidden susurrus of machinery as they stepped out into a small bare entryroom. Another guard sat there, beside a desk. Past him was a small door of immense solidity, the door of a vault.

"You'll have to leave everything metallic here," said Lang. "A steel object could jump so fiercely as to injure you. Your watch would be ruined. Even coins could get uncomfortably hot ... eddy currents, you know. We're about to go through the strongest magnetic field ever generated."

Silently, dry-mouthed, Radek piled his things on the desk. Lang operated a combination lock on the door. "There are nervous effects too," he said. "The field is actually strong enough to influence the electric discharges of your synapses. Be prepared for a few nasty seconds. Follow me and walk fast."

The door opened on a low, narrow corridor several meters long. Radek felt his heart bump crazily, his vision blurred, there was panic screaming in his brain and a sweating tingle in his skin. Stumbling through nightmare, he made it to the end.

The horror faded. They were in another room, with storage facilities and what resembled a spaceship's airlock in the opposite wall. Lang grinned shakily. "No fun, is it?"

"What's it for?" gasped Radek.

"To keep charged particles out of here. And the whole set of chambers is 500 meters underground, sheathed in ten meters of lead brick and surrounded by tanks of heavy water. This is the only place in the Solar System, I imagine, where cosmic rays never come."

"You mean—"

Lang knocked out his pipe and left it in a gobboon. He opened the lockers to reveal a set of airsuits, complete with helmets and oxygen tanks. "We put these on before going any further," he said.

"Infection on the other side?"

"We're the infected ones. Come on, I'll help you."

As they scrambled into the equipment, Lang added conversationally: "This place has to have all its own stuff, of course ... its own electric generators and so on. The ultimate power source is isotopically pure carbon burned in oxygen. We use a nuclear reactor to create the magnetic field itself, but no atomic energy is allowed inside it." He led the way into the airlock, closed it, and started the pumps. "We have to flush out all the normal air and substitute that from the inner chambers."

"How about food? Barwell said food was prepared in the kitchens and brought here."

"Synthesized out of elements recovered from waste products. We do cook it topside, taking precautions. A few radioactive atoms get in, but not enough to matter as long as we're careful. We're so cramped for space down here we have to make some compromises."

"I think—" Radek fell silent. As the lock was evacuated, his unjointed airsuit spreadeagled and held him prisoner, but he hardly noticed. There was too much else to think about, too much to grasp at once.

Not till the cycle was over and they had gone through the lock did he speak again. Then it came harsh and jerky: "I begin to understand. How long has this gone on?"

"It started about 200 years ago ... an early Institute project." Lang's voice was somehow tinny over the helmet phone. "At that time, it wasn't possible to make really pure isotopes in quantity, so there were only limited results, but it was enough to justify further research. This particular set of chambers and chemical elements is 150 years old. A spectacular success, a brilliant confirmation, from the very beginning ... and the Institute has never dared reveal it. Maybe they should have, back then—maybe people could have taken the news—but not now. These days the knowledge would whip men into a murderous rage of frustration; they wouldn't believe the truth, they wouldn't dare believe, and God alone knows what they'd do."

Looking around, Radek saw a large, plastic-lined room, filled with cages. As the lights went on, white rats and guinea pigs stirred sleepily. One of the rats came up to nibble at the wires and regard the humans from beady pink eyes.