a thousand, a million. Plenty of room and plenty of power from each probability sun."

"More than one on a planet?" said Mishnoff sourly.

Ching knew exactly what he meant. When probability patterns had first been put to use, sole ownership of a planet had been powerful inducement for early settlers. It appealed to the snob and despot in every one. What man so poor, ran the slogan, as not to have an empire larger than Genghis Khan's? To introduce multiple settling now would outrage everyone.

Ching said, with a shrug, "All right, it would take psychological preparation. So what? That's what it took to start the whole deal in the first place."

"And food?" asked Mishnoff.

"You know we're putting hydroponic works and yeast plants in other probability patterns. And if we had to, we could cultivate their soil."

"Wearing space suits and importing oxygen."

"We could reduce carbon dioxide for oxygen till the plants got going and they'd do the job after that."

"Given a million years."

"Mishnoff, the trouble with you," Ching said, "is you read too many ancient history books. You're an obstructionist."

But Ching was too good-natured really to mean that, and Mishnoff continued to read books and to worry. Mishnoff longed for the day he could get up the courage necessary to see the Head of the Section and put right out in plain view-bang, like that-exactly what it was that was troubling him.

But now, a Mr. Clarence Rimbro faced them, perspiring slightly and toweringly angry at the fact that it had taken him the better part of two days to reach this far into the Bureau.

He reached his exposition's climax by saying, "And / say the planet is inhabited and I don't propose to stand for it."

Having listened to his story in full, Ching tried the soothing approach. He said, "Noise like that is probably just some natural phenomenon."

"What kind of natural phenomenon?" demanded Rimbro. "I want an investigation. If it's a natural phenomenon, I want to know what kind. I say the place is inhabited. It has life on it, by Heaven, and I'm not paying rent on a planet to share it. And with dinosaurs, from the sound of it."

"Come, Mr. Rimbro, how long have you lived on your Earth?"

"Fifteen and a half years."

"And has there ever been any evidence of life?"

"There is now, and, as a citizen with a production record classified as A-I, I demand an investigation."

"Of course we'll investigate, sir, but we just want to assure you now that everything is all right. Do you realize how carefully we select our probability patterns?"

"I'm an accountant. I have a pretty good idea," said Rimbro at once.

"Then surely you know our computers cannot fail us. They never pick a

probability which has been picked before. They can't possibly. And they're geared to select only probability patterns in which Earth has a carbon dioxide atmosphere, one in which plant life, and therefore animal life, has never developed. Because if plants had evolved, the carbon dioxide would have been reduced to oxygen. Do you understand?"

"I understand it all very well and I'm not here for lectures," said Rimbro. "I want an investigation out of you and nothing else. It is quite humiliating to think I may be sharing my world, my own world, with something or other, and I don't propose to endure it."

"No, of course not," muttered Ching, avoiding Mishnoff's sardonic glance. "We'll be there before night."

They were on their way to the twisting place with full equipment.

Mishnoff said, "I want to ask you something. Why do you go through that There's no need to worry, sir' routine? They always worry anyway. Where does it get you?"

"I've got to try. They shouldn 't worry," said Ching petulantly. "Ever hear of a carbon dioxide planet that was inhabited? Besides, Rimbro is the type that starts rumors. I can spot them. By the time he's through, if he's encouraged, he'll say his sun went nova."

"That happens sometimes," said Mishnoff.

"So? One house is wiped out and one family dies. See, you're an obstructionist. In the old times, the times you like, if there were a flood in China or someplace, thousands of people would die. And that's out of a population of a measly billion or two."

Mishnoff muttered, "How do you know the Rimbro planet doesn't have life on it?"

"Carbon dioxide atmosphere."

"But suppose-" It was no use. Mishnoff couldn't say it. He finished lamely, "Suppose plant and animal life develops that can live on carbon 2j dioxide."

"It's never been observed."

"In an infinite number of worlds, anything can happen." He finished that 1 in a whisper. "Everything must happen."

"Chances are one in a duodecillion," said Ching, shrugging.

They arrived at the twisting point then, and, having utilized the freight twist for their vehicle (thus sending it into the Rimbro storage area), they entered the Rimbro probability pattern themselves. First Ching, then Mishnoff.

"A nice house," said Ching, with satisfaction. "Very nice model. Good taste." "Hear anything?" asked Mishnoff.

, "No."

Ching wandered into the garden. "Hey," he yelled. "Rhode Island Reds."

Mishnoff followed, looking up at the glass roof. The sun looked like the sun of a trillion other Earths.

He said absently, "There could be plant life, just starting out. The carbon dioxide might just be starting to drop in concentration. The computer would never know."

"And it would take millions of years for animal life to begin and millions more for it to come out of the sea."

"It doesn't have to follow that pattern."

Ching put an arm about his partner's shoulder. "You brood. Someday, you'll tell me what's really bothering you, instead of just hinting, and we can straighten you out."

Mishnoff shrugged off the encircling arm with an annoyed frown. Ching's tolerance was always hard to bear. He began, "Let's not psychothera-pize-" He broke off, then whispered, "Listen."

There was a distant rumble. Again.

They placed the seismograph in the center of the room and activated the force field that penetrated downward and bound it rigidly to bedrock. They watched the quivering needle record the shocks.

Mishnoff said, "Surface waves only. Very superficial. It's not underground."

Ching looked a little more dismal, "What is it then?"

"1 think," said Mishnoff, "we'd better find out." His face was gray with apprehension. "We'll have to set up a seismograph at another point and get a fix on the focus of the disturbance."

"Obviously," said Ching. "I'll go out with the other seismograph. You stay here."

"No," said Mishnoff, with energy. "/'// go out."

Mishnoff felt terrified, but he had no choice. If this were it, he would be prepared. He could get a warning through. Sending out an unsuspecting Ching would be disastrous. Nor could he warn Ching, who would certainly never believe him.

But since Mishnoff was not cast in the heroic mold, he trembled as he got into his oxygen suit and fumbled the disrupter as he tried to dissolve the force field locally in order to free the emergency exit.

"Any reason you want to go, particularly?" asked Ching, watching the other's inept manipulations. "I'm willing."

"It's all right. I'm going out," said Mishnoff, out of a dry throat, and stepped into the lock that led out onto the desolate surface of a lifeless Earth. A presumably lifeless Earth.

The sight was not unfamiliar to Mishnoff. He had seen its like dozens of times. Bare rock, weathered by wind and rain, crusted and powdered with

sand in the gullies; a small and noisy brook beating itself against its stony course. All brown and gray; no sign of green. No sound of life.

Yet the sun was the same and, when night fell, the constellations would be the same.

The situation of the dwelling place was in that region which on Earth proper would be called Labrador. (It was Labrador here, too, really. It had been calculated that in not more than one out of a quadrillion or so Earths were there significant changes in the geological development. The continents were everywhere recognizable down to quite small details.)