Lightning

'They'd have won the war,' Chris said.

Stefan asked for water and drank half a glass this time. He wanted to hold the glass in his good hand, but he was shaking too much; water slopped on the bedclothes, and Laura had to help him.

When he spoke again, Stefan's voice wavered at times. 'Because the time traveler exists outside of time during his journey, he is not only able to move in time but geographically, as well. Picture him hanging above the earth, unmoving, as the globe turns below him. That's not what he does, of course, but it's easier to see that image than to imagine him hovering in another dimension. Now, as he hangs above the world, it turns below him, and if his journey to the future is gauged properly, he can travel to a precise time at which he will find himself in Berlin, the same city he left years before. But if he chooses to travel a few hours more or less, the world will have turned that much more beneath him, and he will arrive at a different place on its surface. The calculations to achieve a precise arrival are monumentally difficult in my era, 1944—'

'But they'd be easy these days,' Chris said, 'with computers.'

Shifting in discomfort against the pillows that propped him up, putting his trembling right hand against his wounded left shoulder as if to quell the pain by his own touch, he said, 'Teams of German physicists, accompanied by Gestapo, were sent secretly to various cities in Europe and the United States in the year 1985, to accumulate vital information on the making of nuclear weapons. The material they were after was not classified or difficult to find. With what they already knew from their own researches, they could obtain the rest from textbooks and scientific publications readily available at any major university library in '85. Four days before I departed the institute for the last time, those teams returned from '85 to March 1944, with material that would give the Third Reich a nuclear arsenal before the autumn of that year. They were to spend a few weeks studying the material at the institute before deciding how and where to introduce that knowledge into the German nuclear program without revealing how it had been obtained. I knew then that I had to destroy the institute and everything it contained, key personnel as well as files, to prevent a future shaped by Adolf Hitler.'

As Laura and Chris listened, rapt, Stefan Krieger told them how he had planted explosives in the institute, how on the last of his days in '44 he had shot Penlovski, Januskaya, and Volkaw, and had programmed the time gate to bring him to Laura in present-day America.

But something had gone wrong at the last minute, as Stefan was leaving. The public power supply failed. The RAF had bombed Berlin for the first time in January that year, and the U.S. bombers had made the first daylight runs on March 6, so the power supply had been interrupted often, not merely due to bomb damage but also because of the work of saboteurs. It was to guard against such interruptions that the gate itself was powered by a secure generator. Stefan heard no bombers that day when, wounded by Kokoschka, he had crawled into the gate, so apparently the power failed because of saboteurs.

'And the timer on the explosives stopped. The gate was not destroyed. It's still open back there, and they can come after us. And… they can still win the war.'

Laura was getting another headache. She put her fingertips to her temples. 'But wait. Hitler can't have succeeded in building atomic weapons and winning World War Two, because we don't live in a world where that happened. You don't have to worry. Somehow, in spite of all the knowledge they took back through the gate, they obviously failed to develop a nuclear arsenal.'

'No,' he said. 'They've failed so far, but we can't assume they will continue to fail. To those men at the institute in Berlin in 1944, their past is immutable, as I have said. They cannot travel backward in time and change their own past. But they can change their future and ours, because a time traveler's future is mutable; he can take steps to alter it.'

'But his future is my past,' Laura said. 'And if the past can't be changed, how can he change mine?'

'Yeah,' Chris said. 'Paradox.'

Laura said, 'Listen, I haven't spent the last thirty-four years in a world ruled by Adolf Hitler and his heirs; therefore, in spite of the gate, Hitler failed.'

Stefan's expression was dismal. 'If time travel were invented now, in 1989, that past of which you speak — World War Two and every event since — would be unalterable. You could not change it, for nature's rule against backward time-travel and time-travel paradoxes would apply to you. But time travel has not been discovered here — or rediscovered. The time travelers at the institute in Berlin in '44 are free to change their future, apparently, and though they will simultaneously be changing your past, nothing in the laws of nature will stop them. And there you have the greatest paradox of all — the only one that for some reason nature seems to allow.'

'You're saying they could still build nuclear weapons back then with the information they got in '85,' Laura said, 'and win the war?'

'Yes. Unless the institute is destroyed first.'

'And what then? Suddenly, all around us, we find things changed, find ourselves living under Nazism?'

'Yes. And you won't even know what's happened, because you will be a different person than you are now. Your entire past will never have occurred. You will have lived a different past altogether, and you will remember nothing else, none of what has happened to you in this life because this life will never have existed. You will think the world has always been as it is, that there was never a world in which Hitler lost.' What he was proposing terrified and appalled her because it made life seem even more fragile than she had always thought it was. The world under her feet suddenly seemed no more real than the world of a dream; it was apt to dissolve without warning and send her tumbling into a great, dark void.

With growing horror she said, 'If they change the world in which I grew up, I might never have met Danny, never married.'

'I might never have been born,' Chris said.

She reached to Chris and put a hand on his arm, not only to reassure him but to reassure herself of his current solidity. 'I might not have been born myself. Everything I've seen, the good and bad of the world that's been since 1944… it'll all wash away like an elaborate sandcastle, and a new reality will exist in its place.'

'A new and worse reality,' Stefan said, clearly exhausted by the effort he had made to explain what was at stake.

'In that new world, I might never have written my novels.'

'Or if you wrote novels,' Stefan said, 'they would be different from those you've done in this life, grotesque works produced by an artist laboring under the rule of an oppressive government, in the iron fist of Nazi censorship.'

'If those guys build the atom bomb in 1944,' Chris said, 'then we'll all just crumble into dust and blow away.'

'Not literally. But like dust, yes,' Stefan Krieger agreed. 'Gone, with no trace that we've ever been.'

'We've gotta stop them,' Chris said.

'If we can,' Stefan agreed. 'But first we've got to stay alive in this reality, and that might not be easy.'

Stefan needed to relieve himself, and Laura helped him into the motel bathroom, handling him as if she were a nurse accustomed to matter-of-fact dealings with the plumbing of sick men. By the time she returned him to the bed, she was worried about him again; though he was muscular, he felt limp, clammy, and he was frighteningly weak.

She told him briefly about the shoot-out at Brenkshaw's, through which he had remained comatose. 'If these assassins are coming from the past instead of the future, how do they know where to find us? How did they know in 1944 that we'd be at Dr. Brenkshaw's when we were, forty-five years later?'

'To find you,' Stefan said, 'they made two trips. First, they went farther into the future, a couple of days farther, to this coming weekend perhaps, to see if you had shown up anywhere by then. If you hadn't — and apparently you had not — then they started checking the public record. Back issues of newspapers, for one thing. They looked for the stories about the shooting at your house last night, and in those stories they read that you'd taken a wounded man to Brenkshaw's place in San Bernardino. So they simply returned to '44 and made a second trip — this time to Dr. Brenkshaw's in the early hours of this morning, January 11.'

'They can hopscotch around us,' Chris told Laura. 'They can pop ahead in time to see where we show up, then they pick and choose the easiest place along the time stream to ambush us. It's sorta like… if we were cowboys and the Indians were all psychic.'