Suddenly Ryan froze.

He was still staring fixedly when the scene winked out and there was nothing. Nothing at all. The meters changed reading. Across the time map the arms moved calmly, tracing their lines.

In the last moment Ryan had looked directly into the man's face. The pain-contorted face. The features had been twisted, screwed up out of shape. And the horn-rimmed glasses were gone. But there was no doubt – it was Schonerman.

Ryan sat down. He ran a shaking hand through his hair.

"You're certain?" Kastner said.

"Yes. He must have come out of the sleep very quickly. It reacts differently on each person. And he was at the far end of the room. He must have come out of it and followed after us."

"Was he badly injured?"

"I don't know."

Kastner opened his briefcase. "Anyhow, we have the papers."

Ryan nodded, only half hearing. Schonerman injured, blasted, his clothing on fire. That had not been part of the plan.

But more important – had it been part of history?

For ftie first time the ramification of what they had done was beginning to emerge in his mind. Their own concern had been to obtain Schonerman's papers, so that USIC could make use of the artificial brain. Properly used, Schonerman's discovery could have great value in aiding the restoration of demolished Terra. Armies of worker-robots replanting and rebuilding. A mechanical army to make Terra fertile again. Robots could do in a generation what humans would toil at for years. Terra could be reborn.

But in returning to the past had they introduced new factors? Had a new past been created? Had some kind of balance been upset?

Ryan stood up and paced back and forth.

"What is it?" Kastner said. "We got the papers."

"I know."

"USIC will be pleased. The League can expect aid from now on. Whatever it wants. This will set up USIC forever. After all, USIC will manufacture the robots. Worker-robots. The end of human labor. Machines instead of men to work the ground."

Ryan nodded. "Fine."

"Then what's wrong?"

"I'm worried about our continuum."

"What are you worried about?"

Ryan crossed to the control board and studied the time map. The ship was moving back toward the present, the arms tracing a path back. "I'm worried about new factors we may have introduced into past continuums. There's no record of Schonerman being injured. There's no record of this event. It may have set a different causal chain into motion."

"Like what?"

"I don't know. But I intend to find out. We're going to make a stop right away and discover what new factors we've set into motion."

Ryan moved the ship into a continuum immediately following the Schonerman incident. It was early October, a little over a week later. He landed the ship in a farmer's field outside of Des Moines, Iowa, at sunset. A cold autumn night with the ground hard and brittle underfoot.

Ryan and Kastner walked into town, Kastner holding tightly onto his briefcase. Des Moines had been bombed by Russian guided missiles. Most of the industrial sections were gone. Only military men and construction workers still remained in the city. The civilian population had been evacuated.

Animals roamed around the deserted streets, looking for food. Glass and debris lay everywhere. The city was cold and desolate. The streets were gutted and wrecked from the fires following the bombing. The autumn air was heavy with the decaying smells of vast heaps of rubble and bodies mixed together in mounds at intersections and open lots.

From a boarded-up newsstand Ryan stole a copy of a news magazine, Week Review. The magazine was damp and covered with mold. Kastner put it into his briefcase and they returned to the time ship. Occasional soldiers passed them, moving weapons and equipment out of the city. No one challenged them.

They reached the time ship and entered, locking the hatch behind them. The fields around them were deserted. The farm building had been burned down, and the crops were withered and dead. In the driveway the remains of a ruined automobile lay on its side, a charred wreck. A group of ugly pigs nosed around the remains of the farmhouse, searching for something to eat.

Ryan sat down, opened the magazine. He studied it for a long time, turning the damp pages slowly.

"What do you see?" Kastner asked.

"All about the war. It's still in the opening stages. Soviet guided missiles dropping down. American disk bombs showering all over Russia."

"Any mention of Schonerman?"

"Nothing I can find. Too much else going on." Ryan went on studying the magazine. Finally, on one of the back pages, he found what he was looking for. A small item, only a paragraph long.

SOVIET AGENTS SURPRISED

A group of Soviet agents, attempting to demolish a Government research station at Harristown, Kansas, were fired on by guards and quickly routed. The agents escaped, after attempting to slip past the guards into the work offices of the station. Passing themselves off as FBI men, the Soviet agents tried to gain entry as the early morning shift was beginning work. Alert guards intercepted them and gave chase. No damage was done to the research labs or equipment. Two guards and one worker were killed in the encounter. The names of the guards

Ryan clutched the magazine.

"What is it?" Kastner hurried over.

Ryan read the rest of the article. He laid down the magazine, pushing it slowly towards Kastner.

"What is it?" Kastner searched the page.

"Schonerman died. Killed by the blast. We killed him. We've changed the past."

Ryan stood up and walked to the port. He lit a cigarette, some of his composure returning. "We set up new factors and started a new line of events. There's no telling where it will end."

"What do you mean?"

"Someone else may discover the artificial brain. Maybe the shift will rectify itself. The time flow will resume its regular course."

"Why should it?"

"I don't know. As it stands, we killed him and stole his papers. There's no way the Government can get hold of his work. They won't even know it ever existed. Unless someone else does the same work, covers the same material -"

"How will we know?"

"We'll have to take more looks. It's the only way to find out."

Ryan selected the year 2051.

In 2051 the first claws had begun to appear. The Soviets had almost won the war. The UN was beginning to bring out the claws in the last desperate attempt to turn the tide of the war.

Ryan landed the time ship at the top of a ridge. Below them a level plain stretched out, criss-crossed with ruins and barbed wire and the remains of weapons.

Kastner unscrewed the hatch and stepped gingerly out onto the ground.

"Be careful," Ryan said. "Remember the claws."

Kastner drew his blast gun. "I'll remember."

"At this stage they were small. About a foot long. Metal. They hid down in the ash. The humanoid types hadn't come into existence, yet."

The sun was high in the sky. It was about noon. The air was warm and thick. Clouds of ash rolled across the ground, blown by the wind.

Suddenly Kastner tensed. "Look. What's that? Coming along the road."

A truck bumped slowly toward them, a heavy brown truck, loaded with soldiers. The truck made its way along the road to i the base of the ridge. Ryan drew his blast gun. He and Kastner stood ready.

The truck stopped. Some of the soldiers leaped down and started up the side of the ridge, striding through the ash.

"Get set," Ryan murmured.

The soldiers reached them, halted a few feet away. Ryan and Kastner stood silently, their blast guns up.

One of the soldiers laughed. "Put them away. Don't you know the war's over?"

"Over?"