Poul Anderson

If you went back to, I would guess, 1946, and worked to prevent your parents’ marriage in 1947, you would still have existed in that year; you would not go out of existence just because you had influenced events. The same would apply even if you had only been in 1946 one microsecond before shooting the man who would otherwise have become your father.

Events are the result of a complex. There are no single causes. That’s why it’s so hard to change history. If I went back to, say, the Middle Ages, and shot one of FDR’s Dutch forebears, he’ll still be born in the late nineteenth century—because he and his genes resulted fom the entire world of his ancestors, and there’d have been compensation. But evey so often, a really key event does occur. Some one happening is a nexus of so many world lines that its outcome is decisive for the whole future.

Now, then. There is one point on which I must set you right. The end of the world is not coming in two years. This I know.

But we are mortal men. And we have free will. The fixed-time concept need not, logically, produce fatalism; after all, Herries, man’s will is itself one of the links in teh causal chain. I suspect that this irrational fatalism is an important reason why twentieth-century civilization is approaching suicide. If we think we know our future is unchangeable, if our every action is foreordained, if we are doomed already, what’s the use of trying? Why go through all the pain of thought, of seeking an answer and struggling to make others accept it? But if we really believed in ourselves, we woiuld look for a solution, and find one.

In the case of a missing man, you were not required to search for him just because a record somewhere said you had done so. But how else would you stand a chance of finding him? You might possibly go back and thereby change events so that you did find him after all—in which case the report you filed would “always” have recorded your success, and you alone would know the “former” truth.

Thin lightnings winked from above. The cloven air boomed behind them. He felt a chill, deeper than the night cold. But he eased his pace. There was no more reason for hurry.

Thin lightnings winked from above. The cloven air boomed behind them. He felt a chill, deeper than the night cold. But he eased his pace. There was no more reason for hurry.

Your world is a slope and you roll down it all the time. Down and down until you wear out and die.

Disgust would be the simplest word.

The homesickeness, though, that’s what eats you. Little things you never noticed. Some particular food, the way people walk, the games played, the small-talk topics. Even the constellations. They're different in the future. The sun has traveled that far in its galactic orbit.

A series of parallel black lines, several inches apart, extended from it, some distance across the corridor floor. At the head of each was a brief inscription, in no alphabet he could recognize. But every ten feet or so a number was added. He saw 4950, 4951, 4952. . .

She was lean, though full enough in hips and firm breasts to please any man, and long-limbed, swan-necked, head proudly held. That head was dolichocephalic but wide across brow and cheeks, tapering toward the chin, with, a classically straight nose and a full and mobile mouth which was a touch too big for conventional beauty. Arching brows and sooty lashes framed large bright eyes whose hazel shifted momentarily from leaf-green to storm-gray. Her black hair, thick and wavy, fell past her shoulders; a white streak ran back from the forehead. Except for suntan, a dusting of freckles, a few fine wrinkles and crow’s-feet, a beginning dryness, her skin was clear and fair. He guessed her age as about equal to his.

No, no, no. I suppose it’s simply a logical impossibility to change the past, same as it’s logically impossible for a uniformly colored spot to be both red and green.

The Mediterranean floor lay ten thousand feet below sea level. The inflow took most of that drop within a fifty-mile strait. Its volume amounted to ten thousand cubic miles a year, a hundred Victoria Falls or a thousand Niagaras.

He swept out of the cell, through space and through time, at light-speed across unseen prairies, into the storms that raged down a great particle accelerator.

For us, approximately eight Terrestrial years have passed. It turns out that the T-machine is indeed a time machine of sorts, as well as a space transporter. The Betans—the beings whom we followed—calculated our course to bring us out near the date when we left.

If Tyre explodes, why, here we’ll be, but our ancestors, your kids, everything we knew, they won’t. It’ll be a whole different history. Whether whatever is left of the Patrol can restore it—somehow head off the disaster—that’s problematical. I’d call it unlikely.