t was Burckhardt's idea and Swanson despised it, but he went along. He was the type who always went along.

"It's dangerous," he grumbled worriedly. "Suppose somebody comes by? They'll spot us and—"

"What have we got to lose?"

Swanson shrugged. "It's dangerous," he said again. But he went along.

Burckhardt's idea was very simple. He was sure of only one thing—the tunnel went somewhere. Martians or Russians, fantastic plot or crazy hallucination, whatever was wrong with Tylerton had an explanation, and the place to look for it was at the end of the tunnel.

They jogged along. It was more than a mile before they began to see an end. They were in luck—at least no one came through the tunnel to spot them. But Swanson had said that it was only at certain hours that the tunnel seemed to be in use.

Always the fifteenth of June. Why? Burckhardt asked himself. Never mind the how. Why?

And falling asleep, completely involuntarily—everyone at the same time, it seemed. And not remembering, never remembering anything—Swanson had said how eagerly he saw Burckhardt again, the morning after Burckhardt had incautiously waited five minutes too many before retreating into the darkroom. When Swanson had come to, Burckhardt was gone. Swanson had seen him in the street that afternoon, but Burckhardt had remembered nothing.

And Swanson had lived his mouse's existence for weeks, hiding in the woodwork at night, stealing out by day to search for Burckhardt in pitiful hope, scurrying around the fringe of life, trying to keep from the deadly eyes of them.

Them. One of "them" was the girl named April Horn. It was by seeing her walk carelessly into a telephone booth and never come out that Swanson had found the tunnel. Another was the man at the cigar stand in Burckhardt's office building. There were more, at least a dozen that Swanson knew of or suspected.

They were easy enough to spot, once you knew where to look—for they, alone in Tylerton, changed their roles from day to day. Burckhardt was on that 8:51 bus, every morning of every day-that-was-June-15th, never different by a hair or a moment. But April Horn was sometimes gaudy in the cellophane skirt, giving away candy or cigarettes; sometimes plainly dressed; sometimes not seen by Swanson at all.

Russians? Martians? Whatever they were, what could they be hoping to gain from this mad masquerade?

Burckhardt didn't know the answer—but perhaps it lay beyond the door at the end of the tunnel. They listened carefully and heard distant sounds that could not quite be made out, but nothing that seemed dangerous. They slipped through.

And, through a wide chamber and up a flight of steps, they found they were in what Burckhardt recognized as the Contro Chemicals plant.

---

obody was in sight. By itself, that was not so very odd—the automatized factory had never had very many persons in it. But Burckhardt remembered, from his single visit, the endless, ceaseless busyness of the plant, the valves that opened and closed, the vats that emptied themselves and filled themselves and stirred and cooked and chemically tasted the bubbling liquids they held inside themselves. The plant was never populated, but it was never still.

Only—now it was still. Except for the distant sounds, there was no breath of life in it. The captive electronic minds were sending out no commands; the coils and relays were at rest.

Burckhardt said, "Come on." Swanson reluctantly followed him through the tangled aisles of stainless steel columns and tanks.

They walked as though they were in the presence of the dead. In a way, they were, for what were the automatons that once had run the factory, if not corpses? The machines were controlled by computers that were really not computers at all, but the electronic analogues of living brains. And if they were turned off, were they not dead? For each had once been a human mind.

Take a master petroleum chemist, infinitely skilled in the separation of crude oil into its fractions. Strap him down, probe into his brain with searching electronic needles. The machine scans the patterns of the mind, translates what it sees into charts and sine waves. Impress these same waves on a robot computer and you have your chemist. Or a thousand copies of your chemist, if you wish, with all of his knowledge and skill, and no human limitations at all.

Put a dozen copies of him into a plant and they will run it all, twenty-four hours a day, seven days of every week, never tiring, never overlooking anything, never forgetting....

Swanson stepped up closer to Burckhardt. "I'm scared," he said.

They were across the room now and the sounds were louder. They were not machine sounds, but voices; Burckhardt moved cautiously up to a door and dared to peer around it.

It was a smaller room, lined with television screens, each one—a dozen or more, at least—with a man or woman sitting before it, staring into the screen and dictating notes into a recorder. The viewers dialed from scene to scene; no two screens ever showed the same picture.

The pictures seemed to have little in common. One was a store, where a girl dressed like April Horn was demonstrating home freezers. One was a series of shots of kitchens. Burckhardt caught a glimpse of what looked like the cigar stand in his office building.

It was baffling and Burckhardt would have loved to stand there and puzzle it out, but it was too busy a place. There was the chance that someone would look their way or walk out and find them.

---

hey found another room. This one was empty. It was an office, large and sumptuous. It had a desk, littered with papers. Burckhardt stared at them, briefly at first—then, as the words on one of them caught his attention, with incredulous fascination.

He snatched up the topmost sheet, scanned it, and another, while Swanson was frenziedly searching through the drawers.

Burckhardt swore unbelievingly and dropped the papers to the desk.

Swanson, hardly noticing, yelped with delight: "Look!" He dragged a gun from the desk. "And it's loaded, too!"

Burckhardt stared at him blankly, trying to assimilate what he had read. Then, as he realized what Swanson had said, Burckhardt's eyes sparked. "Good man!" he cried. "We'll take it. We're getting out of here with that gun, Swanson. And we're going to the police! Not the cops in Tylerton, but the F.B.I., maybe. Take a look at this!"

The sheaf he handed Swanson was headed: "Test Area Progress Report. Subject: Marlin Cigarettes Campaign." It was mostly tabulated figures that made little sense to Burckhardt and Swanson, but at the end was a summary that said:

Swanson looked up from the paper into Burckhardt's eyes. "I don't get it," he complained.

Burckhardt said, "I don't blame you. It's crazy, but it fits the facts, Swanson, it fits the facts. They aren't Russians and they aren't Martians. These people are advertising men! Somehow—heaven knows how they did it—they've taken Tylerton over. They've got us, all of us, you and me and twenty or thirty thousand other people, right under their thumbs.

"Maybe they hypnotize us and maybe it's something else; but however they do it, what happens is that they let us live a day at a time. They pour advertising into us the whole damned day long. And at the end of the day, they see what happened—and then they wash the day out of our minds and start again the next day with different advertising."

---

wanson's jaw was hanging. He managed to close it and swallow. "Nuts!" he said flatly.

Burckhardt shook his head. "Sure, it sounds crazy—but this whole thing is crazy. How else would you explain it? You can't deny that most of Tylerton lives the same day over and over again. You've seen it! And that's the crazy part and we have to admit that that's true—unless we are the crazy ones. And once you admit that somebody, somehow, knows how to accomplish that, the rest of it makes all kinds of sense.

"Think of it, Swanson! They test every last detail before they spend a nickel on advertising! Do you have any idea what that means? Lord knows how much money is involved, but I know for a fact that some companies spend twenty or thirty million dollars a year on advertising. Multiply it, say, by a hundred companies. Say that every one of them learns how to cut its advertising cost by only ten per cent. And that's peanuts, believe me!

"If they know in advance what's going to work, they can cut their costs in half—maybe to less than half, I don't know. But that's saving two or three hundred million dollars a year—and if they pay only ten or twenty per cent of that for the use of Tylerton, it's still dirt cheap for them and a fortune for whoever took over Tylerton."

Swanson licked his lips. "You mean," he offered hesitantly, "that we're a—well, a kind of captive audience?"

Burckhardt frowned. "Not exactly." He thought for a minute. "You know how a doctor tests something like penicillin? He sets up a series of little colonies of germs on gelatine disks and he tries the stuff on one after another, changing it a little each time. Well, that's us—we're the germs, Swanson. Only it's even more efficient than that. They don't have to test more than one colony, because they can use it over and over again."

It was too hard for Swanson to take in. He only said: "What do we do about it?"

"We go to the police. They can't use human beings for guinea pigs!"

"How do we get to the police?"

Burckhardt hesitated. "I think—" he began slowly. "Sure. This place is the office of somebody important. We've got a gun. We'll stay right here until he comes along. And he'll get us out of here."

Simple and direct. Swanson subsided and found a place to sit, against the wall, out of sight of the door. Burckhardt took up a position behind the door itself—

And waited.

---

he wait was not as long as it might have been. Half an hour, perhaps. Then Burckhardt heard approaching voices and had time for a swift whisper to Swanson before he flattened himself against the wall.

It was a man's voice, and a girl's. The man was saying, "—reason why you couldn't report on the phone? You're ruining your whole day's test! What the devil's the matter with you, Janet?"

"I'm sorry, Mr. Dorchin," she said in a sweet, clear tone. "I thought it was important."

The man grumbled, "Important! One lousy unit out of twenty-one thousand."

"But it's the Burckhardt one, Mr. Dorchin. Again. And the way he got out of sight, he must have had some help."

"All right, all right. It doesn't matter, Janet; the Choco-Bite program is ahead of schedule anyhow. As long as you're this far, come on in the office and make out your worksheet. And don't worry about the Burckhardt business. He's probably just wandering around. We'll pick him up tonight and—"

They were inside the door. Burckhardt kicked it shut and pointed the gun.

"That's what you think," he said triumphantly.

It was worth the terrified hours, the bewildered sense of insanity, the confusion and fear. It was the most satisfying sensation Burckhardt had ever had in his life. The expression on the man's face was one he had read about but never actually seen: Dorchin's mouth fell open and his eyes went wide, and though he managed to make a sound that might have been a question, it was not in words.

The girl was almost as surprised. And Burckhardt, looking at her, knew why her voice had been so familiar. The girl was the one who had introduced herself to him as April Horn.

Dorchin recovered himself quickly. "Is this the one?" he asked sharply.

The girl said, "Yes."

Dorchin nodded. "I take it back. You were right. Uh, you—Burckhardt. What do you want?"

---

wanson piped up, "Watch him! He might have another gun."

"Search him then," Burckhardt said. "I'll tell you what we want, Dorchin. We want you to come along with us to the FBI and explain to them how you can get away with kidnapping twenty thousand people."

"Kidnapping?" Dorchin snorted. "That's ridiculous, man! Put that gun away—you can't get away with this!"

Burckhardt hefted the gun grimly. "I think I can."

Dorchin looked furious and sick—but, oddly, not afraid. "Damn it—" he started to bellow, then closed his mouth and swallowed. "Listen," he said persuasively, "you're making a big mistake. I haven't kidnapped anybody, believe me!"

"I don't believe you," said Burckhardt bluntly. "Why should I?"

"But it's true! Take my word for it!"

Burckhardt shook his head. "The FBI can take your word if they like. We'll find out. Now how do we get out of here?"

Dorchin opened his mouth to argue.

Burckhardt blazed: "Don't get in my way! I'm willing to kill you if I have to. Don't you understand that? I've gone through two days of hell and every second of it I blame on you. Kill you? It would be a pleasure and I don't have a thing in the world to lose! Get us out of here!"

Dorchin's face went suddenly opaque. He seemed about to move; but the blonde girl he had called Janet slipped between him and the gun.

"Please!" she begged Burckhardt. "You don't understand. You mustn't shoot!"

"Get out of my way!"

"But, Mr. Burckhardt—"

She never finished. Dorchin, his face unreadable, headed for the door. Burckhardt had been pushed one degree too far. He swung the gun, bellowing. The girl called out sharply. He pulled the trigger. Closing on him with pity and pleading in her eyes, she came again between the gun and the man.

Burckhardt aimed low instinctively, to cripple, not to kill. But his aim was not good.

The pistol bullet caught her in the pit of the stomach.

---

orchin was out and away, the door slamming behind him, his footsteps racing into the distance.

Burckhardt hurled the gun across the room and jumped to the girl.

Swanson was moaning. "That finishes us, Burckhardt. Oh, why did you do it? We could have got away. We could have gone to the police. We were practically out of here! We—"

Burckhardt wasn't listening. He was kneeling beside the girl. She lay flat on her back, arms helter-skelter. There was no blood, hardly any sign of the wound; but the position in which she lay was one that no living human being could have held.

Yet she wasn't dead.

She wasn't dead—and Burckhardt, frozen beside her, thought: She isn't alive, either.

There was no pulse, but there was a rhythmic ticking of the outstretched fingers of one hand.

There was no sound of breathing, but there was a hissing, sizzling noise.

The eyes were open and they were looking at Burckhardt. There was neither fear nor pain in them, only a pity deeper than the Pit.

She said, through lips that writhed erratically, "Don't—worry, Mr. Burckhardt. I'm—all right."

Burckhardt rocked back on his haunches, staring. Where there should have been blood, there was a clean break of a substance that was not flesh; and a curl of thin golden-copper wire.

Burckhardt moistened his lips.

"You're a robot," he said.

The girl tried to nod. The twitching lips said, "I am. And so are you."