When the sharp snap of a pistol shot came from the half-finished building, Karnes wasn't anywhere near the sandpile that received the slug. He was fifteen feet away, behind the much more reliable protection of a neat stack of cement bags that provided cover all the way to a window in the empty shell of brick and steel before him.

Three hundred yards behind him, the still-burning inferno of what had been the Assembly Section of Carlson Spacecraft sent a reddish, unevenly pulsating light over the surrounding territory, punctuating the redness with intermittent flashes of blue-white from flaring magnesium.

For an instant, Karnes let himself hope that the shot might be heard at the scene of the blaze, but only for an instant. The roar of fire, men, and machine would be too much for a little pop like that.

He moved quietly along the stacked cement bags, and eased himself over the sill of the gaping window into the building. He was in a little hallway. Somewhere ahead and to his left would be a door that would lead into the main hallway where James Avery, alias James Harvey, alias half-a-dozen other names, was waiting to take another pot-shot at the sandpile.

The passageway was longer than he had thought, and he realized that he might have been just a little careless in coming in through the window. With the firelight at his back, he might make a pretty good target from farther down the hall, or from any of the dark, empty rooms that would someday be officers'.

Then he found it. The slight light from the main hallway came through enough to show him where to turn.

Keeping in the darkness, Karnes' eyes surveyed the broad hallway for several seconds before he spotted the movement near a stairway. After he knew where to look, it was easy to make out the man's crouched figure.

Karnes thought: I can't call to him to surrender. I can't let him get away. I can't sneak across that hall to stick my gun in his ribs. And, above all, I cannot let him get away with that microfilm.

Hell, there's only one thing I can do.

Karnes lifted his gun, aimed carefully at the figure, and fired.

---

Avery must have had a fairly tight grip on his own weapon, because when Karnes' slug hit him, it went off once before his body spread itself untidily across the freshly set cement. Then the gun fell out of the dead hand and slid a few feet, spinning in silly little circles.

Karnes approached the corpse cautiously, just in case it wasn't a corpse, but it took only a moment to see that the caution had been unnecessary. He knelt, rolled the body over, unfastened the pants, pulled them down to the knees and stripped off the ribbon of adhesive tape that he knew would be on the inside of the thigh. Underneath it were four little squares of thin plastic.

As he looked at the precious microfilm in his hand, he sensed something odd. If he had been equipped with the properly developed muscles to do so, he would have pricked his ears. There was a soft footstep behind him.

He spun around on his heel, his gun ready. There was another man standing at the top of the shadowy stairway.

Karnes stood up slowly, his weapon still levelled.

"Come down from there slowly, with your hands in the air!"

The man didn't move immediately, and, although Karnes couldn't see his face clearly in the shimmering shadows, he had the definite impression that there was a grin on it. When the man did move, it was to turn quickly and run down the upper hallway, with a shot ringing behind him.

Karnes made the top of the stairway and sent another shot after the fleeing man, whose outline was easily visible against the pre-dawn light that was now beginning to come in through a window at the far end of the hall.

The figure kept running, and Karnes went after him, firing twice more as he ran.

Who taught you to shoot, dead-eye? he thought, as the man continued to run.

At the end of the hall, the man turned abruptly into one of the offices-to-be, his pursuer only five yards behind him.

---

Afterwards, Karnes thought it over time after time, trying to find some flaw or illusion in what he saw. But, much as he hated to believe his own senses, he remained convinced.

The broad window shed enough light to see everything in the room, but there wasn't much in it except for the slightly iridescent gray object in the center.

It was an oblate spheroid, about seven feet high and eight or nine feet through. As Karnes came through the door, he saw the man step through the seemingly solid material into the flattened globe.

Then globe, man and all, vanished. The room was empty.

Karnes checked his headlong rush into the room and peered around in the early morning gloom. For a full minute his brain refused even to attempt rationalizing what he had seen. He looked wildly around, but there was no one there. Suddenly he felt very foolish.

All right. So men can run into round gray things and vanish. Now use a little sense and look around.

There was something else in the room. Karnes knelt and looked at the little object that lay on the floor a few feet from where the gray globe had been. A cigarette case; one of those flat, coat-pocket jobs with a jet black enamel surface laid over tiny checked squares that would be absolutely useless for picking up fingerprints. If there were any prints, they'd be on the inside.

He started to pick it up and realized he must still be a bit confused; his hands were full. His right held the heavy automatic, and between the thumb and forefinger of his left were the four tiny sheets of microfilm.

Karnes holstered the pistol, took an envelope from his pocket, put the films in it, replaced the envelope, and picked up the cigarette case. It was, he thought, a rather odd-looking affair. It—

"Awright, you. Stand up slow, with your hands where I can see 'em."

Great God, thought Karnes, I didn't know they were holding a tea party in this building. He did as he was told.

There were two of them at the door, both wearing the uniform of Carlson Spacecraft. Plant protection squad.

"Who are you, bud?" asked the heavy-jawed one who had spoken before. "And whataya doin' here?"

Karnes, keeping his hands high, said: "Take my billfold out of my hip pocket."

"Okay. But first get over against that wall and lean forward." Evidently the man was either an ex-cop or a reader of detective stories.

---

When Karnes had braced himself against the wall, the guard went through his pockets, all of them, but he didn't take anything out except the pistol and the billfold.

The card in the special case of the wallet changed the guard's manner amazingly.

"Oh," he said softly. "Government, huh? Gee, I'm sorry, sir, but we didn't know—"

Karnes straightened up, and put his hands down. The cigarette case that had been in his right hand all along dropped into his coat pocket.

"That's all right," he said. "Did you see the lad at the foot of the stairs?"

"Sure. Jim Avery. Worked in Assembly. What happened to him?"

"He got in the way of the bullet. Resisting arrest. He's the jasper that set off the little incendiaries that started that mess out there. We've been watching him for months, now, but we didn't get word of this cute stroke until too late."

The guard looked puzzled. "Jim Avery. But why'd he want to do that?"

Karnes looked straight at him. "Leaguer!"

The guard nodded. You never could tell when the League would pop up like that.

Even after the collapse of Communism after the war, the world hadn't learned anything, it seemed. The Eurasian League had seemed, at first, to be patterned after the Western world's United Nations, but it hadn't worked out that way.

The League was jealous of the UN lead in space travel, for one thing, and they had neither the money nor the know-how to catch up. The UN might have given them help, but, as the French delegate had remarked: "For what reason should we arm a potential enemy?"

After all, they argued, with the threat of the UN's Moonbase hanging over the League to keep them peaceful, why should we give them spaceships so they can destroy Moonbase?

The Eurasian League had been quiet for a good many years, brooding, but behaving. Then, three years ago, Moonbase had vanished in a flash of actinic light, leaving only a new minor crater in the crust of Luna.

There was no proof of anything, of course. It had to be written off as an accident. But from that day on, the League had become increasingly bolder; their policy was: "Smash the UN and take the planets for ourselves!"

And now, with Carlson Spacecraft going up in flames, they seemed to be getting closer to their goal.

---

Karnes accepted his weapon and billfold from the guard and led them back down the stairway. "Would one of you guys phone the State Police? They'll want to know what happened."

The State Police copters came and went, taking Karnes and the late Mr. Avery with them, and leaving behind the now dying glow of Carlson Spacecraft.

There were innumerable forms to fill out and affidavits to make; there was a long-distance call to UN headquarters in New York to verify Karnes' identity. And Karnes asked to borrow the police lab for an hour or so.

That evening, he caught the rocket for Long Island.

As the SR-37 floated through the hard vacuum five hundred miles above central Nebraska, Karnes leaned back in his seat, turning the odd cigarette case over and over in his hands.

Except for the neat, even checking that covered it, the little three-by-four inch object was entirely featureless. There were no catches or hinges, or even any line of cleavage around the edge. He had already found that it wouldn't open.

Whatever it was, it was most definitely not a cigarette case.

The X-ray plates had shown it to be perfectly homogeneous throughout.

As far as I can see, thought Karnes, it's nothing but a piece of acid-proof plastic, except that the specific gravity is way the hell too high. Maybe if I had cut it open, I could have—

Karnes didn't push anything on the case, of that he was sure. Nor did he squeeze, shake, or rub it in any unusual way. But something happened; something which he was convinced came from the case in his hands.

He had the definite impression of something akin to a high-pressure firehose squirting from the interior of the case, through his skull, and into and over his brain, washing it and filling it. Little rivers of knowledge trickled down through the convolutions of his brain, collected in pools, and soaked in.

---

He was never sure just how long the process took but it was certainly not more than a second or two. Afterwards, he just sat there, staring.

From far across the unimaginable depths of the galaxy, fighting its way through the vast, tenuous dust clouds of interstellar space, came a voice: "Are you ill, sir?"

Karnes looked up at the stewardess. "Oh. Oh, no. No, I'm all right. Just thinking. I'm perfectly all right."

He looked at the "cigarette case" again. He knew what it was, now. There wasn't any English word for it, but he guessed "mind impressor" would come close.

It had done just that; impressed his mind with knowledge he should not have; the record of something he had no business knowing.

And he wished to Heaven he didn't!

This, Karnes considered, is a problem. The stuff is so alien! Just a series of things I know, but can't explain. Like a dream; you know all about it, but it's practically impossible to explain it to anybody else.

At the spaceport, he was met by an official car. George Lansberg, one of the New York agents, was sitting in the back seat.

"Hi, sleuth. I heard you were coming in, so I asked to meet you." He lowered his voice as Karnes got in and the car pulled away from the parking lot. "How about our boy, Avery?"

Karnes shook his head. "Too late. Thirty million bucks worth of material lost and Avery lost too."

"How come?"

"Had to kill him to keep him from getting away with these."

He showed Lansberg the microfilm squares.

"The photocircuit inserts for the new autopilot. We'd lose everything if the League ever got its hands on these."

"Didn't learn anything from Avery, eh?" Lansberg asked.

"Not a thing." Karnes lapsed into silence. He didn't feel it necessary to mention the mind impressor just yet.

Lansberg stuck a cigarette into his mouth and talked around it as he lit it.

"We've got something you'll be getting in on, now that Avery is taken care of. We've got a fellow named Brittain, real name Bretinov, who is holed up in a little apartment in Brooklyn. He's the sector head for that section, and we know who his informers are, and who he gives orders to. What we don't know is who gives orders to him.

"Now we have it set up for Brittain to get his hands on some very honest-looking, but strictly phony stuff for him to pass on to the next echelon. Then we just sit around and watch until he does pass it."

---

Karnes found he was listening to Lansberg with only half an ear. His brain was still buzzing with things he'd never heard of, trying to fit things he had always known in with things he knew now but had never known before. Damn that "cigarette case"!

"Sounds like fun," he answered Lansberg.

"Yeah. Great. Well, here we are." They had driven to the Long Island Spaceways Building which also housed the local office.

They got out and went into the building, up the elevator, down a corridor, and into an office suite.

Lansberg said: "I'll wait for you here. We'll get some coffee afterwards."

The redhead behind the front desk smiled up at Karnes.

"Go on in; he's expecting you."

"I don't know whether I ought to leave you out here with Georgie or not," Karnes grinned. "I think he has designs."

"Oh, goodie!" she grinned back.

My, my aren't we clever! His thought was bitter, but his face didn't show it.

Before he went in, he straightened his collar before the wall mirror. He noticed that his plain, slightly tanned face still looked the same as ever. Same ordinary gray-green eyes, same ordinary nose.

Chum, you look perfectly sane. You are perfectly sane. But who in hell would believe it?

It wouldn't, after all, do any good for him to tell anyone anything he had found. No matter what the answer was, there wasn't anything he could do about it. There wasn't anything anyone could do about it.

Thus, Karnes' report to his superior was short, to the point, and censored.

That evening, Karnes sat in his apartment, chain-smoking, and staring out the window. Finally, he mashed out a stub, stood up, and said aloud: "Maybe if I write it down I can get it straight."

He sat down in front of the portable on his desk, rolled in a sheet of paper, and put his fingers on the keys. Then, for a long time, he just sat there, turning it over and over in his mind. Finally, he began to type.

Karnes stopped again and reread the paragraph he had just written. It sounded different when it was on paper. The dates, for instance, he had put in parentheses because that was the way he had understood them. But he knew that whoever had made the mind-impressor didn't use the same calendar he was used to.

He frowned at the paper, then went on typing.

Karnes stopped. That was all there was. Except—except for one more little tail end of thought. He tapped the keys again.

(Continued on Stratum Two)

Whatever in hell that means, he thought.

He sat back in his chair and went over the two sheets of typed paper. It wasn't complete, not by a long shot. There were little tones of meaning that a printed, or even a spoken word couldn't put over. There were evidences of a vast and certainly superhuman civilization; of an alien and yet somehow completely human way of thinking.

But that was the gist of it. The man he had seen in that new building at Carlson Spacecraft was no ordinary human being.

That, however, didn't bother Karnes half so much as the gray globe the man had disappeared into after he had been shot at. And Karnes knew, now, that the shots probably hadn't missed.

The globe was one of two things. And the intruder had been one of two groups.

(A) One of the Surveyors of Ancient Earth, in which case the globe had been a—well, a time machine. Or

(B) A student, in which case the machine was a type of spacecraft.

The question was: Which?

If it were (A), then he and the world around him were real, living, working out their own destinies toward the end point represented by the man in the gray globe.

But if it were (B)—

Then this was the Shrine, and he and all the rest of Earth were nothing but glorified textbooks!

And there would come crises on the Shrine, duplicates of the crises on old Earth. Except that they wouldn't be permitted to happen. The poor ignorant people on the Shrine had to be coddled, like the children they were. Damn!

Karnes crumpled the sheets of paper in his hands, twisting them savagely. Then he methodically tore them into bits.

---

When the first dawnlight touched the sea, Karnes was watching it out the east window. It had been twenty-four hours since he had seen the superman walk into his gray globe and vanish.

All night, he had been searching his brain for some clue that would tell him which of the two choices he should believe in. And he couldn't bring himself to believe in either.

Once he had thought: Why do I believe, then, what the impressor said? Why not just forget it?

But that didn't help. He did believe it. That alien instrument had impressed his mind, not only with the facts themselves, but with an absolute faith that they were facts. There was no room for doubt; the knowledge imparted to his mind was true, and he knew it.

For a time, he had been comforted by the thought that the gray globe must be a time machine because of the way it had vanished. It was very comforting until he realized that travel to the stars and beyond didn't necessarily mean a spaceship as he knew spaceships. Teleportation—

Now, with the dawn, Karnes knew there was only one thing he could do.

Somehow, somewhere, there would be other clues—clues a man who knew what to look for might find. The Galactics couldn't be perfect, or they wouldn't have let him get the mind impressor in his hands. Ergo, somewhere they would slip again.

Karnes knew he would spend the rest of his life looking for that one slip. He had to know the truth, one way or another.

Or he might not stay sane.

---

Lansberg picked him up at eight in a police copter. As they floated toward New York, Karnes' mind settled itself into one cold purpose; a purpose that lay at the base of his brain, waiting.

Lansberg was saying: "—and one of Brittain's men got the stuff last night. He hadn't passed it on to Brittain himself yet this morning, but he very probably will have by the time we get there.

"We've rigged it up so that Brittain will have to pass it to his superior by tomorrow or it will be worthless. When he does, we'll follow it right to the top."

"If we've got every loophole plugged," said Karnes, "we ought to take them easy."

"Brother, I hope so! It took us eight months to get Brittain all hot and bothered over the bait, and another two months to give it to him in a way that wouldn't make him suspicious.

"It's restricted material, of course, so that we can pin a subversive activities rap on them, at least, if not espionage. But we had to argue like hell to keep it restricted; the Spatial Commission was ready to release it, since it's really relatively harmless."

Karnes looked absently at the thin line of smoke wiggling from Lansberg's cigarette.

"You know," he said, "there are times when I wish this war would come right out in the open. Actually, we've been fighting the League for years, but we don't admit it. There have been little disagreements and incidents until the devil won't have it. But it's still supposed to be a 'worry war'."

Lansberg shrugged. "It will get hot just as soon as the Eurasian League figures they are far enough along in spacecraft construction to get the Martian colonies if they win. Then they'll try to smash us before we can retaliate; then, and not before.

"We can't start it. Our only hope is that when they start, they'll underestimate us. Say, what's that you're fooling with?"

The sudden change of subject startled Karnes for an instant. He looked at the mind impressor in his hands. He had been toying with it incessantly, hoping it would repeat its performance, or perhaps give additional information.

"This?" He covered quickly. "It's a—a puzzle. One of those plastic puzzles." Maybe it doesn't work on the same person twice. If I can get George to fool around with it, he might hit the right combination again.

"Hmmm. How does it work?" George seemed interested.

Karnes handed it to him. "It has a couple of little sliding weights inside it. You have to turn the thing just right to unlock it, then it comes apart when you slide out a section of the surface. Try it."

---

Lansberg took it, turned it this way and that, moving his hands over the surface. Karnes watched him for several minutes, but there didn't seem to be any results.

Lansberg looked up from his labors. "I give up. I can't even see where it's supposed to come apart, and I can't feel any weights sliding inside it. Show me how it works."

Karnes thought fast. "Why do you think I was fiddling with it? I don't know how it works. A friend of mine bet me a ten spot that I couldn't figure out the combination."

Lansberg looked back at the impressor in his hands. "Could he do it?"

"A snap. I watched him twice, and I still didn't get it."

"Mmm. Interesting." George went back to work on the "puzzle."

Just before they landed on the roof of the UN annex, Lansberg handed the impressor back to Karnes. It had obviously failed to do what either of them had hoped it would.

"It's your baby," Lansberg said, shaking his head. "All I have to say is it's a hell of a way to earn ten bucks."

Karnes grinned and dropped the thing back in his coat pocket.

By the time that evening had rolled around, Karnes was beginning to get just a little bored. He and Lansberg had been in and out of the New York office in record time. Then they had spent a few hours with New York's Finest and the District Attorney, lining up a net to pick up all the little rats involved.

After that, there was nothing to do but wait.

Karnes slept a couple of hours to catch up, read two magazines from cover to cover, and played eight games of solitaire. He was getting itchy.

His brain kept crackling. What's the matter with me? I ought to be thinking about this Brittain fellow instead of—

But, after all, what did Brittain matter? According to the records, he was born Alex Bretinov, in Marseilles, France, in nineteen sixty-eight. His father, a dyed-in-the-wool Old Guard Communist, had been born in Minsk in nineteen forty.

Or had he been wound up, and his clockwork started in January of nineteen fifty-three?

The radio popped. "Eighteen. Alert. Brittain just left his place on foot. Carson, Reymann following. Over."

Lansberg dropped his magazine. "He seems to be heading for the Big Boy—I hope."

The ground car followed him to a subway, and two men on foot followed him in from Flatbush Avenue.

---

Some hours later, after much devious turning, dodging, and switching, Brittain climbed into a taxi on the corner of Park Avenue and Forty-seventh Street, evidently feeling he had ditched any tails he might have had.

Karnes and Lansberg were right behind him in a radio car.

The cab headed due south on Park Avenue, following it until it became Fourth, swung right at Tenth Street, past Grace Church, across Broadway. At Sixth, it angled left toward Greenwich Village.

"Somewhere in the Village, nickels to knotholes," Lansberg guessed as he turned to follow.

Karnes, at the radio, was giving rapid-fire directions over the scrambler-equipped transceiver. By this time, several carloads of agents and police were converging on the cab from every direction. From high above, could be heard the faint hum of 'copters.

Lansberg was exultant. "We've got them for once! And the goods on every essobee in the place."

The cars hummed smoothly through the broad streets, past the shabby-genteel apartment neighborhood. Back in the early sixties, some of these buildings had been high-priced hotels, but the Village had gone to pot since the seventies.

A few minutes later, the cab pulled up in front of an imposing looking building of slightly tarnished aluminum paneling. Brittain got out, paid his fare, and went inside.

As the cab pulled away, Karnes gave orders for it to be picked up a few blocks away, just in case.

The rest of the vehicles began to surround the building.

Karnes, meanwhile, followed Brittain into the foyer of the apartment hotel. It was almost a mistake. Brittain hadn't gone in. Evidently attracted by the footsteps following him, he turned and looked back out. Karnes wasn't more than ten feet away.

Just pretend you live here, thought Karnes, and bully-boy will never know the difference.

He walked right on up to the doorway, pretending not to notice Brittain. Evidently, the saboteur was a little flustered, not quite knowing who Karnes was. He, too, pretended that he had no suspicions. He pressed a buzzer on the panel to announce himself to a guest. Karnes noticed it was 523; a fifth floor button.

The front door, inside the foyer, was one of those gadgets with an electric lock that doesn't open unless you either have a key to the building or can get a friend who lives there to let you in.

When Karnes saw Brittain press the buzzer, he waited a second and took a chance.

"Here," he said, fishing in his pocket, "I'll let you in." That ought to give him the impression I live here.

Brittain smiled fetchingly. "Thanks, but I—"

Bzzzz! The old-fashioned lock announced that it was open. Karnes stopped fishing and opened the door, letting Brittain follow him in. He stayed in the lead to the elevator, and pushed the button marked "4."

"You getting off before four?" he asked conversationally.

"No."

The elevator slid on up to four without another word being said by either man.

Karnes was judging the speed of the elevator, estimating the time it took for the doors to open as they did so, and making quick mental comparisons with his own ability to climb stairs at a run. The elevator was an old one, and fairly slow—

When the doors slid open, he stepped out and began to walk easily down the hall toward the stairway. When the elevator clicked shut, he broke into a run and hit the stairway at top speed, his long legs taking the steps three at a time.

The stairway was poorly lit, since it was hardly ever used, and, at the fifth floor, he was able to conceal himself in the darkness as Brittain turned up the hall toward 523.

Karnes looked closely at his surroundings for the first time. There was a well-worn, but not ragged, nylon carpet on the floor, dull chrome railing on the stair bannisters, and the halls were lit by old-fashioned glo-plates in the ceiling. The place was inexpensive, but not cheap.

Having made sure that Brittain actually had entered 523, he stepped back toward the elevator in order to notify Lansberg.

A sudden voice said: "You lookin' for-a somebody, meester?"

Karnes turned. An elderly man with a heavy mustache and a heavy body stood partway up the stairs, clad in slacks and shirt.

"Who are you?" frowned Karnes.

"I'm Amati, the supratendent. Why?" The scowl was heavy.

Karnes couldn't take any chances. The man might be perfectly okay, but—

---

Lansberg's steps sounded, coming up the stairs. With him was a Manhattan Squad officer of the Police Department.

"Shhh, Mr. Amati. C'mere a minute," said the cop.

"Oh. Lootenant Carnotti. Whatsa—"

"Shhhhhh! C'mere, I said, and be quiet!"

"You know this man?" Lansberg asked the policeman softly, indicating Amati.

"Sure. He's okay."

Lansberg turned to the superintendent. "What do you know about the guy who just came in?"

Amati seemed to have realized that something serious was going on, for his voice dropped to a conspiratorial whisper. "I dunno. I don't-a see who it is. Whatsa goin' on, Lootenant Carnotti?"

"What about Apartment 523? Who lives there?" asked Karnes.

"Oh, them? Meester and Meeses Seigert. Artists. Sheesa paint pictures, heesa make statues." Then Amati's eyes widened knowingly. "Ohhh! You guys da Vice Squad, eh? I theenk theresa someteeng fonny about them!"

Footsteps sounded coming down the stairs from above.

"We watched the indicator needle on the elevator door in the lobby, and I signalled the 'copters on the roof," Lansberg whispered.

The hallway began to fill quietly with police.

Lieutenant Carnotti assigned one of the men to watch Amati, mainly in order to keep him out of the way, and Karnes led the men down the hall towards 523, guns drawn.

Karnes knocked boldly on the door.

"Yeah? Who is it?" asked someone inside.

Karnes pitched his voice a little lower than normal, and said: "It's-a me, Meester Amati, only me, the soopratendant."

The imitation wasn't perfect, but the muffling effect of the door would offset any imperfections.

"Oh, sure, Mr. Amati. Just a sec." There was a short pause, filled with muffled conversation, then somebody was unlocking the door.

---

Things began to happen fast. As the door came open, Karnes saw that it had one of those inside chain locks on it that permit the door to be opened only a few inches. Without hesitation, he threw his weight against the door. Lansberg was right behind him.

Under the combined weight of the two men, the chain ripped out of the woodwork, permitting the door to swing free. As it did so, it slammed into the face of the man who had opened it, knocking him backwards.

There were seven or eight other men and two women in the room. One of the men already had a heavy pistol out and was aiming it at the doorway. Karnes dropped to the floor and fired just as the other's pistol went off.

The high-velocity three millimeter slug whined through the air above Karnes' head and buried itself in Lansberg's shoulder. Lansberg dropped, spun halfway around from the shock. His knees hit Karnes in the back.

Karnes lurched forward a little, and regained his balance. Something flew out of his coat pocket and skittered across the floor. Karnes didn't notice what it was until one of the men across the room picked it up.

Brittain had picked up the mind impressor!

Karnes was aware that there were more men behind him firing at another of the conspirators who had made the mistake of drawing a weapon, but he wasn't interested too much. He was watching Brittain.

It only took seconds, but to Karnes it seemed like long minutes. Brittain had evidently thought the impressor was a weapon when he picked it up, and, after seeing his mistake, had started to throw it at the door. Then the impressor shimmered slightly, as though there were a hot radiator between the observor and the object. Brittain stopped, paralyzed, his eyes widening.

Then he gasped and threw the impressor against the floor as hard as he could.

"NO!" he screamed, "IT'S A LIE!"

The impressor struck the floor and broke. From its shattered interior came a blinding multi-colored glare. Then there was darkness. Karnes fainted.

When Karnes awoke, one of the policemen was shaking him.

"Wake up, Mr. Karnes, wake up!"

Karnes sat up abruptly. "What happened?" He had no time to be original.

"I don't know for sure. One of the Leaguers threw a gas bomb of some sort, and it knocked out everyone in the room. Funny, though, it even knocked out all the Leaguers. When the rest of the boys came in, everybody was out cold on the floor. Most of them are coming out of it now, except for two of the Leaguers. They got some lead in them, though, not gas."

Karnes stood up. He felt a little dizzy, but otherwise there wasn't anything wrong. He surveyed the room.

On the floor was a slightly yellowed spot where the impressor had flared and vanished. Lansberg was unconscious with a copiously bleeding right shoulder. Two other men were rapidly being brought around by the police. Three of the League agents were still out; nobody tried to wake them up, they were being handcuffed.

One of the women was crying and cursing the "damned filthy Nations police" over one of the bodies, and the other woman was sitting stonily, staring at her handcuffs with a faint sneer.

"Where's Brittain?" roared Karnes. The man was nowhere in the room.

"Gone," said one of the cops. "Evidently he skipped out while the rest of us were unconscious. He was the guy who threw the bomb."

Karnes glanced at his watch. One sixteen in the morning. They had been out about twelve or thirteen minutes.

"Where the devil did he go? How in—"

Lieutenant Carnotti came up to him, a look of self-disgust on his face. "I know how he got away, Mr. Karnes; I just talked to the boys on the roof. He grabbed a uniform coat and cap off Sergeant Joseph while he was out and commandeered a 'copter on the roof."

---

Karnes didn't wait for further information. He ran out into the hall and into the open elevator. Within less than a minute, he was on the roof.

One cop was speaking rapidly into a transmitter.

"—number 3765. Left about ten minutes ago, supposedly for the hospital. Officer Powers in the 'copter with him."

He cut off and looked at Karnes, who was standing over him. His gun was out before he spoke. "Who are you, buddy."

Karnes told him who he was. The cop looked skeptical. Karnes didn't have his hat on, and his clothes were a bit rumpled after his nap on the floor.

Karnes didn't need to say anything; another policeman was going through his pockets, and he found the billfold. As soon as they saw the forgeproof identity card, they relaxed.

"Sorry, Mr. Karnes," said the man at the transceiver, "but we've already let one man get away."

Karnes nodded. "I know. Pure blind luck that his suit was almost the same shade as that gray uniform you guys wear, or he'd never have got away with it. All he needed was the jacket and cap."

"Have any idea which way he went?"

The cop shrugged. "He came up here and told us that three men had been shot down below and some more gassed. He said Mr. Lansberg had sent him for a hospital call. Then he jumped in a 'copter with Powers and headed northeast. We didn't pay much attention. After all, he was wearing a sergeant's stripes."

Northeast. That would be toward Long Island. But, naturally, he would circle; he wouldn't be dumb enough to head in the right direction until he was out of sight. Or would he?

"Get on that radio again," he told the radioman, "—and tell them I want that man alive. Get that—alive!"

"Right." The officer switched on his microphone and began to talk.

Karnes pinched the bridge of his nose and closed his eyes in an attempt to concentrate. With Lansberg shot up, that put the Brittain case in his hands. Theoretically, he should be pumping the prisoners down below to find out how much higher the spy ring went.

---

But his real interest lay in Brittain, himself. There was no doubt that he had received another message from the impressor before he had thrown it down.

Evidently, when the thing broke, the unknown energies which powered it had short-circuited, paralyzing everyone in the room with their mind-impressing effect.

Then why hadn't it affected Brittain? Perhaps his recent exposure to a normal dosage had immunized him. There was no way of knowing—there never would be.

But what was the message Brittain had received from the impressor that would make him react so violently? It couldn't be the same one that he, Karnes, had received.

Continued on Stratum Two!

Sure; that was it! Like the pages in a book. He, himself, had been hit with page one; Brittain had page two. Page three? Lost forever.

Why hadn't they found that 'copter by now? It ought to be easy enough to spot.

He walked over to the edge of the building and looked down. The police were herding the prisoners into the ground cars. Presently, they were gone. One of the police officers touched his shoulder.

"Ready to go, Mr. Karnes?"

Karnes nodded and climbed into the 'copter. The machine lifted and headed toward the Central Police Station.

He was still trying to think when the phone rang. The policeman picked it up.

"3217. Brown speaking. Oh? Yeah, just a second. It's for you, Mr. Karnes."

Karnes took the instrument. "Karnes speaking."

"Radio Central, Mr. Karnes," came the voice. "We just got some more on Brittain. About ten minutes ago, he abandoned the police 'copter. Officer Powers was in the seat, shot through the head. We'll get the essobee on a murder rap, now."

"Where was the 'copter abandoned?"

Radio Central told him and went on: "Funny thing was, he didn't try to hide it or anything. And he stole another 'copter from a private citizen. We're trying to get the description now. I'll call you if anything further comes in."

"Fine." Karnes hung up. The address where Brittain had left the 'copter was in almost a direct line between the apartment building and Long Island Spaceport. But if Brittain were actually heading there, why should he leave such a broad and obvious trail?

He turned to the officer who was driving the 'copter.

"I've got a hunch. Swivel this thing around and head for Long Island. I've got a funny feeling that Brittain will be there. He—"

The phone rang again, and Karnes grabbed it.

"Mr. Karnes, we've found that civilian's 'copter! It's at Long Island Spaceport! Just a second, the stuff's still coming in." Pause. "Get this: A man answering to Brittain's description bought a ticket for the West Coast rocket.

"As you know, that's UN territory, and we have no jurisdiction. The rocket is sealed for takeoff, but they're holding it for us until you get there!"

"Right! I'm headed there now!" he answered quickly.

It was twelve minutes later that the police 'copter settled just outside the rocket enclosure. Karnes had already notified the pilot to be ready for him. He sprinted up the ramp and stood at the airlock of the transcontinental rocket.

It sighed open, and Karnes stepped inside. He was met by a frightened stewardess.

"Tell him to get in here and not to try any funny stuff!" snapped a voice from the passenger cabin.

Brittain was standing at the forward end of the passenger compartment with a levelled gun.

The rocket was tilted at forty-five degrees for the takeoff, and the passenger's seats had swiveled with a section of the flooring to keep them level, which gave the effect of a stairway which climbed toward the pilot's cabin in the forward section of the ship. Brittain's position was at the top of the stairway.

Karnes raised his hands and kept them carefully away from his hip holster.

"All right," called Brittain, "Close that door and get this ship off the ground."

The pilot could hear him through the intercom system. The airlock door slid shut again.

"You and the stewardess get into a seat," the spy continued sharply. "If you try anything funny, I start shooting the other passengers if I can't hit you."

Karnes saw then what hold Brittain had on the pilot. The rocketeer couldn't afford to risk the lives of his passengers.

He and the stewardess slid into the acceleration seats and strapped themselves in. Brittain stepped down the tiered floor and took a rear seat near a frightened-looking blonde girl.

"Anything funny, and Blondie here gets a bullet. Okay, pilot. Take her up!"

There was a faint hiss, and then the rockets began their throbbing roar. Acceleration pressure began to shove the passengers back in their seats. Karnes leaned back and tried—successfully—to suppress the smile of triumph that kept trying to come to his lips.

Brittain had finally made a mistake.

One hundred and twenty-five miles over Pennsylvania, the rockets cut out, and the ship went into free fall. And Brittain's mistake became evident.

With the abrupt cessation of weight, the padded acceleration seats expanded again, pressing the passengers up against their safety straps. But Brittain had failed to strap himself in.

---

The expanding seat shoved forward and toward the ceiling. Before he could recover from his surprise, Karnes had undone his own seat belt and snapped his body through the air toward Brittain. They collided with a thump and Brittain's body slammed against the roof of the cabin with agonizing force. The gun came out of his hand and clanged against a wall, then drifted off harmlessly. Brittain was out cold.

Karnes handcuffed him securely and, with the stewardess' help, tugged him back to the baggage compartment. One of the passengers was quietly retching into a vacuum disposal chute.

With Brittain securely strapped into an empty baggage rack, Karnes swam back to the pilot's compartment, pulling himself along the railing that ran along the floor.

The pilot looked relieved. "Thank heaven you got the devil! He got wise when we delayed the takeoff, and threatened to start shooting my passengers. There wasn't a thing I could do."

"I know. Let me use your radio."

It took a couple of minutes to get UN International Investigation on the hookup, but Karnes finally was talking to his superior in the UN office. He reported what had happened.

"Fine, Karnes," came the tight-beamed voice. "Now, here's something else you ought to know. Our radar net has spotted robot rockets coming in over the Pole. So far, five of them have been hit by interceptor rockets, but we don't have them all by a long shot.

"Evidently, the League feels that they're ready to slam us, now that they've got Moonbase and two of our spacecraft plants out of the way. The war is on, Karnes."

Karnes acknowledged, they cut the connection.

There was one thing burning hotly in his brain. Brittain had fled New York without seeming to care how far they traced him or what kind of trail he left behind. Why?

He jerked open the door of the pilot's cabin, and, not bothering to use the rail, launched himself toward the rear of the ship, flipping himself halfway down to land with his feet against the baggage room door. He pulled the door open and pushed inside.

Brittain was still groggy, so Karnes began slapping his face methodically, rocking his head from side to side.

"Okay! Okay! Stop it!" Brittain yelled, fully awake.

Karnes stopped, and Brittain blinked, owlishly. Karnes' hunch factory was still operating at full blast; he was fairly sure that the lie he was about to tell would have all of the desired effect.

"You didn't really think you could get away, did you, bud?" he asked, nastily. "We're headed back for New York now, and you'll stand trial for murder as well as sabotage and espionage."

Brittain's eyes widened in horror.

"What did that mind impressor tell you?" Karnes went on.

---

Brittain was trying to keep his mouth shut, but at that moment there was a glare of light which flashed bluely through the hard quartz of a nearby window.

From somewhere far to the north, another interceptor rocket had found the atomic warhead of an enemy bomb.

Brittain knew and recognized that flash. He screamed wordlessly and then began to sob like a hysterical child.

Karnes began to slap him again. "Come on, what was it?"

"Don't—don't let them go back to New York! It said—it said—" he gasped and took a deep breath "—WE'LL ALL BE KILLED!" he screamed.

"Why?" Karnes's voice was cold.

"BOMB!" Brittain screamed again.

After a few more minutes of questioning, Karnes finally got the rest of the story from him.

The Galactics had found that on this date a nuclear bomb would get through the UN screen and completely destroy most of Greater New York. Only one other bomb would get through, but it would be thrown off course and land somewhere in the Pacific, having missed Los Angeles entirely.

"Anything else?" asked Karnes after a few seconds of silence from Brittain. "Didn't it say they would have to prevent that?"

Brittain's voice was dull now. "All it said was that the records would have to be preserved. It said that things must go on exactly as before. It said that nothing must interfere with the complete development, whatever that means."

Karnes pushed his way out of the room and back towards the pilot's compartment. What the pilot had to say was no news to Karnes.

"Radio from New York says that a bomb missed LA and hit the ocean. That was a close one."

Karnes nodded silently, and leaned back in the stewardess' seat to think.

---

No wonder Brittain had been so anxious to get out of New York.

New York would be destroyed, but that was inevitable. The thing that had bothered him, his dilemma, was solved.

Was this the real Earth that he lived in, or a museum that had been set up by the Galactics? If it was old Earth, then man would solve his present problems and go on to solve the problem of time travel and interstellar transportation. The present war would be just another little incident in the far past, like the battles of Gettysburg and Agincourt.

---

And if it were the museum Earth? No difference. For the Galactics had decided not to interfere. They had decided to let the race of Earth go on as it was—exactly as it had gone before. It made no difference, really. No difference at all. A perfect duplication of an original was the original, in every meaningful way.

"Funny," said the pilot abruptly, "I'm not getting any signal from New York."

Karnes took a deep breath and bit at his lower lip. But he did not look toward the horror that was New York. The city was gone, but the world was there—solid and real!

You'd better expand your museum a little bit, boys, he thought. We'll need to include Mars and Venus before very long. And then the stars.

---