Two-hundred-and-eighty-five years in the future, the 810-40.04 said.
They sat still, hardly breathing. Vic cleared his throat. And what Is Well, is that where I came from? From 2255 A.D.?
Yes.
But why doesn't he remember that future? Lynda asked, leaning over the table toward the trunk as if it were a person.
Because he never lived it, the computer said.
Wait, Salsbury interrupted. I'm not tracking clearly. When did I live, then?
Never, the computer said. You're an android.
He looked at Lynda; she at him. She took his hand, which was the sign he needed to maintain his confidence. He spoke to the 810-40.04 again. I'm not made of wires and tubes. I bleed real blood.
Android, not robot, the computer said. You were a product of the Artificial Wombs, grown from a chemically simulated egg and a chemically simulated sperm, each with carefully engineered genes. From all appearances, you are a natural born man. You think, feel, and react like a man, like Victor Salsbury who was chosen because data about him had survived the centuries; his work gained renown after his death. You have, it is agreed, a soul like any man, for you are in all ways human except for those differences built into you. They are three. One: in a crisis, you react with more speed than a man should, for your mental process are stimulated by danger and you can tap them with the fluency of some wild animals. Two: you have an ability to produce and use an adrenalin-like substance which is secreted by a mechanism buried in your liver. This has the single drawback of making you highly susceptible to alcoholic beverages, but this cannot be helped. Three: you have great recuperative powers far beyond the normal. Otherwise, you are a man.
If this cause is so important, Victor said, why not send one of those oppressed people back? He would be more fanatical. You would be more certain of his cooperation, though he would not have my recuperative powers or reactions.
That is reason enough, the machine said. But, also, a man cannot travel so far into the past, unfortunately.
Why not?
As he travels backwards, a man grows younger. If he begins his journey as a fifty year old, travels twenty years into the past, he is then thirty. No man can, therefore, return further into the past than his birth date. Since, in our future, the average age under the vacii is only eighty-two, we have no chance of finding a real man old enough to come back to this period and still be an adult when he arrives.
But why didn't I react like a man? Vic asked. He suspected why. The suspicion lingered in the back of his mind, frightening yet tantalizing.
The computer continued in a level tone. The artificial atmosphere of the mechanical wombs can help us achieve many things. The flow of time can be compressed or stretched. In your case, we made the interior of the womb capsule an accelerated time pocket. It took two years to create you, but you were carefully aged 310 years in that time. When you came back into the past in the normal time-flow reversal, you ended up in 1970 as a twenty-five-year-old man.
Salsbury could think of nothing to say, nothing to ask. He could only look at his body, his hands, and think about how old he was how really really old.
Lynda thought of something. If we stop these these vacii and can live a normal life, will Vic live to be 310?
The computer seemed to take a moment for reflection. He will be a fixture of the present, will not wink out of existence. He will live a healthy life, though it is not certain he will grow to be 310. He will not be living a preordained life, but a future of his own choosing. His mortality should be every bit as shaky as anyone's in this era.
You've more or less convinced me the vacii must be stopped, Salsbury said. But why? What are they and where are they from?
They are an intelligent extra-galactic race. Not only have they conquered faster-than-light travel, but probability travel as well. Or at least one probability line of them has.
Salsbury looked properly perplexed, and the computer's sensors must have registered the expression.
Imagine, the computer said, that this is not the only Earth that exists. There are thousands, millions, billions, countless Earths with slightly different histories. There are an infinity of probabilities, all existing in the same space and time, but separated by quasi-dimensional spaces. Traveling from one to the other of these probabilities involves finding the weak spots in the quasi-dimensional spaces, the places where the probabilities almost touch. Once these are found, equipment is erected to weaken these places further until, finally, a bubble develops between the two probabilities, a bubble through which you can pass. At first, living tissue cannot move through the bubble and survive, for it is a vacuum filled with randomly bouncing electrons freed when the quasi-dimensional space is broken down to form the bubble. These electrons have a mass all out of proportion to their size. Tremendous density. They're like bullets that are of micro-micro size; they corrode the flesh, though they do not harm the plasti-steel alloy of the robots specially built to transverse the primitive bubble.
Once on the other side, the robots can bring through equipment to set up a beam generator from this side of the bubble. When the beams from both sides are locked, the bubble becomes a doorway that even flesh can pass through without difficulty. The vacii have sent robots through to destroy you but have not yet opened the bubble to animal transport. They will do that shortly, as soon as they have killed you, or before.
But to return to the origins of the vacii, the lizard-men. They landed on an Earth of one of the other probability lines and conquered it. From there, they spread out in both directions on the plane of probabilities, defeating one counter-Earth after another. We are the seventy-sixth to fall. We have not essentially been conquered from space, but from our own other probabilities. Here, at Harold Jacobi's house, in the summer of 1970, the vacii took over this probability. They established as experimental station, then proceeded to worlds beyond ours, into other probabilities.
Unknown to the vacii manning the station, on this world, our world-the future from which you and I have come-man discovered time travel. It was obvious, at once, to those in our future, that a time machine could be used as a weapon against the vacii rulers. If someone could be sent into the past to stop the vacii takeover of our worldline, the future would be entirely different. Man would be free. And, perhaps, the other vacii empires could fall like dominoes, backwards through the other probability lines they conquered; one Earth becoming free after another.
That was it. But it was too complicated to grasp all its significances in one sitting. Salsbury could only let it settle into his mind where he could later proceed to try to understand it. The lizards in the wall were aliens. But they were coming from a counter-Earth, not directly from the stars. He had been sent from the future of this Earth to stop their invasion before it began
What do you mean by experimental stations? Lynda asked. And what is the future like under the vacii?
The vacii, the 810-40.04 said, are nearly emotionless creatures. Perhaps they do experience love, pity, and hate among themselves, though to a small degree; but they have no feelings toward men. They look to man as an inferior animal to be experimented with. Where man's personality includes creativity and human interaction, the vacii have only scientific curiosity. They live for their experiments. The purpose of the race is to glean knowledge from the universe, or thus has developed their chief philosophy. Man is not the only race they have brought under their rule. There are other species throughout several galaxies. With each new race it subdues, the vacii begins controlled social experiments. How will men, for instance, react in a world of total anarchy? To find out, the vacii produce a world of anarchy and watch for a few centuries. The experiment never ends really, continuing as long as one human being is left alive in that experimental situation. Or maybe they create a world of pure democracy. Or a world ruled by teen-agers. Or they introduce a certain invention into the established society, perhaps a new weapon, perhaps something making genetic control possible. All sorts of things.