"What is a world line?"
"See… the drug relaxes, but your brain is still lawyer-sharp. You live in a particular present because of what happened in the past. Columbus discovered America, the armies of the North won the Civil War, Einstein stated that E = MC2"
He stopped abruptly, and Mark waited for him to go on, but he did not. Why? Because he was waiting for Mark to finish for him. Mark nodded.
"What you are waiting for is for me to ask if there is a world line where Columbus died in infancy, where the South won, and so forth. Is that what you mean?"
"I do. Now, carry the analogy forward."
"If two or three world lines exist, why, more, any number, an infinity of world lines can exist. Infinitely different, eternally separate." Then he was on his feet, shaking despite the drug. "But they are not separate. We are in a different one right now. There is a different world line beyond that door, down those steps-because the ground here is at a different height. Is that true?"
"Yes."
"But why, how… I mean, what is going on out there, what terrible thing is happening?"
"The sun is in the early stages of a change. It is getting warmer, giving out more radiation, and the polar ice caps are beginning to melt. The sea level has risen, drowning the lowest parts of the city This is midwinter, and you saw how warm it is out there. You can imagine what the tropics are like. There has been a breakdown in government as people fled the drowning shorelines. Others have taken advantage of it. The Union of South Africa has capitalized on the deteriorating conditions, and using mercenary troops, has invaded the North American continent. They met little resistance."
"I don't understand-or rather, I do understand what is happening out there, and I believe you, because I saw it for myself. But what can I do about it? Why did you bring me here?"
"You can do nothing about it. I brought you here because we have discovered by experience that the quickest way that someone can be convinced of the multiplicity of worldliness is by bringing them physically to a different world line."
"It is also the best-and quickest-way to discover if they can accept this fact and not break down before this new awareness."
"You have divined the truth. We are, unfortunately, short of time, so wish to determine as soon as possible if recruits will be able to work with us."
"Who is we?"
"In a moment I will tell you. First, do you accept the idea of the multiplicity of world lines?"
"I'm afraid I must. Outside is an inescapable fact. That is not a stage constructed to confuse me. Those dead men are dead forever. How many world lines are there?"
"An infinite number; it is impossible to know. Some differ greatly, some so slightly that it is impossible to mark the difference. Imagine them, if you will, as close together as cards in a pack. If two-dimensional creatures, cluba and hearts, lived on each card, they would be unaware of the other cards and just as unable to reach them. Continue the analogy, drive a nail through all of the cards. Now the other cards can be reached. My people, the 'we' you asked about, are the ones who can do that. We have reached many world lines. Some we cannot reach-some we dare not reach."
"Why?"
"You ask why-after what you saw out there?" For the first time since they had met, Arinix lost his cold detachment. His single eye blazed with fury, and his fists were clenched as he paced the floor. "You saw the filthy things that happen, the death that comes before the absolute death. You see me, and I am typical of my people, maimed, killed, and scarred by a swollen sun that produces more and more hard radiation every year. We escaped our world line, seeking salvation in other world lines, only to discover the awful and ultimate secret. The rot is beginning, going faster and faster all the time. You saw what the world is like beyond that door. Do you understand what I am saying, do the words make any sense to you?
"The sun is going nova. It is the end."
4
"Water," Arinix called out hoarsely, slumping onto the metal bench, his single eye closed now. The inner door opened, and his companion appeared with a pitcher and refilled the glasses. He moved as smoothly as before and seemed ignorant of the black hole in his forehead.
"He is a Sixim," Arinix said, seeing the direction of Mark's gaze. He drank the water so greedily that it ran down his chin. "They are our helpers; we could not do without them. Not our invention. We borrow what we need. They are machines, fabrications of plastic and metal, though there is artificial flesh of some kind involved in their construction. I do not know the details. Their controlling apparatus is somewhere in the armored chest cavity; they are quite invulnerable."
Mark had to ask the question.
"The sun is going nova, you said. Everywhere, in every time line-in my time line?"
Arinix shook his head a weary no. "Not in every line; that is our only salvation. But in too many of them-and the pace is accelerating steadily. Your line-no, not as far as we know. The solar spectrum does not show the characteristic changes. Your line has enough problems as it is, and is one we use for much-needed supplies. There are few of us, always too few, and so much to be done. We must save whom we can and what we can, do it without telling why or how we operate. It is a great work that does not end, and is a most tiring one. But my people are driven, driven insane with hatred, at times, of that bloated, evil thing in the sky. We have survived for centuries in spite of it, maimed and mutated by the radiation it pours out. It was due to a successful mutation that we escaped even as we have, a man of genius who discovered the door between the world lines. But the unsuccessful outnumber a million to one the successful in mutations, and I will not attempt to describe the suffering in my world. You may think me maimed, but I am one of the lucky ones. We have escaped our world line but found the enemy waiting everywhere. We have tried to fight back. We started less than two hundred years ago, and our enemy started millions of years before us. From it we have learned to be ruthless in the war, and we will go on fighting it until we have done everything possible."
"You want me to do something in that world outside the door?"
"No, not there; they are dead. The destruction is too advanced. We can only watch. Closer to the end, we will save what art we can. Things have been noted. We know a culture by its art, don't we? We know a world that way as well. So many gone without record, so much to do."
He drank greedily at the water, slobbering. Perhaps he was mad, Mark thought, partly mad, at least. Hating the sun,trying to fight it, fighting an endlessly losing battle. But… wasn't it worth it? If lives, people, could be saved, wasn't that worth any price, any sacrifice? In his world line, men worked to save endangered species. Arinix and his people worked to save another species-their own.
"What can I do to help?" Mark asked.
"You must find out what happened to our field agent in one of our biggest operations. He is from your world line, the one we call Einstein because it is one of the very few where atomic energy has been released. He is now on Iroquois, which will begin going nova within the century. It is a strange line, with little technology and retarded by monolithic religions. Europe still lives in the dark ages. The Indians rule in North America, and the Six Nations are the most powerful of all. They are a brave and resourceful people, and we had hoped to use them to settle a desert world-we know of many of those. Imagine, if you can, the Earth where life never began, where the seas are empty, the land a desert of sand and rock. We have seeded many of them, and that is wonder to behold, with animal and plant life. Simple enough to introduce seeds of all kinds, and later, when they have been established, to transfer animals there. Mankind is not as easy to transfer. We had great hopes with the Iroquois, but our agent has been reported missing. I have taken time from my own projects to correct the matter. We used War Department records to find you."