Please, he said silently as he wept.

“I love you, Father,” said Rigg. “I will miss you forever. I know I will.”

If that didn’t provoke Father into speech, nothing ever would.

There was no answer.

Rigg turned resolutely and walked back, retracing his own bright path among the trees and underbrush, along the deer path, back to the last spot where he had seen his father alive.

CHAPTER 2

Upsheer

Ram Odin was raised to be a starship pilot. It was his father who adopted the Norse god of the sky as their surname, and it was his father who made sure Ram was absolutely prepared to go into astronaut training two years before the normal time.

Every bit of surplus wealth on Earth had been used to build humanity’s first interstellar colony ships; it took forty years. Under the shadow of moondust that still blocked out more than a third of the sun’s rays from the surface of Earth, the sense of urgency flagged very little, despite the human ability to get used to anything.

Everyone understood how close the human race had come to extinction when the comet swept past Earth and gouged its way into the near face of the moon. Even now, there was no certainty that the Moon’s orbit would restabilize; astronomers were almost evenly divided among those who thought it would sooner or later collide with Earth, and those who thought a new equilibrium would be achieved.

So all who had survived the first terrible years of worldwide cold and famine dedicated themselves to building two identical ships. One would crawl out into space at ten percent of lightspeed, with generation after generation of future colonists living, growing old, and dying inside its closed ecosystem.

The other ship, Ram’s ship, would travel seven years away from the solar system and then make a daring leap into theoretical physics.

Either spacetime could be made to fold, skipping ninety lightyears and putting the colony ship only seven years away from the earthlike planet that was its destination, or the ship would obliterate itself in the attempt . . . or nothing would happen at all, and it would crawl on for nine hundred more years before reaching its new world.

The colonists on Ram’s ship slept their way toward the foldpoint. If all went well, they would remain asleep through the fold and not be wakened until they neared their destination. If nothing happened at all, they would be wakened to begin farming the vast interior, starting the thirty-five generations that the colony must survive until arrival.

Ram alone would remain awake the entire time.

Seven years with only the expendables for company. Once engineered to do work that might kill an irreplaceable human being, the expendables had now been so vastly improved that they could outlive and outwork any human. They also cost far more to make than it cost to train a human to do even a small part of their work.

Still, they were not human. They could not be allowed to make life-and-death decisions while all the humans were asleep. Yet they were such a good simulation of human life that Ram would never be lonely.

•  •  •

For as long as Rigg could remember, Father had been his only home. He could hardly count the rooming house in the village of Fall Ford. The mistress of the house, Nox, didn’t even keep a permanent room for them. If there were travelers filling all the rooms, Father and Rigg slept out in the stable.

Oh, there had been a time when Rigg wondered if perhaps Nox was his mother, and Father had merely neglected to marry her. After all, Father and Nox had spent hours alone together, Father giving Rigg jobs to do so he wouldn’t interrupt them. What were they doing, if not the thing that the village children whispered about, and the older boys laughed about, and the older girls spoke about in hushed voices?

But when Rigg asked Father outright, he had smiled and then took him inside the house and made him ask Nox to her face. So Rigg stammered and said, “Are you my mother?”

For a moment it looked as if she would laugh, but she caught herself at once and instead she ruffled his hair. “If I had ever had a child, I’d have been glad if he’d been one like you. But I’m as barren as a brick, as my husband found to his sorrow before he died, poor man, in the winter of Year Zero, when everyone thought the world would end.”

Yet Nox was something to Father, or they would not have come back to her almost every year, and Father would not have spent those hours alone with her.

Nox knew who Rigg’s mother and sister were. Father had told her, but not Rigg himself. How many other secrets did she know?

Father and Rigg had been trapping in the high country, far upriver from Stashi Falls. Rigg came down the path that ran on the left side of the river, skirting the lake, then coming along the ridge toward the falls. The ridge was like a dam containing the lake, broken only by the gap of the falls. On the one side of the ridge, the land sloped gently down to the icy waters of the lake; on the other side, the land dropped off in a cliff, the Upsheer, that fell three hundred fathoms to the great Forest of Downwater. The cliff ran unbroken thirty leagues to the east and forty leagues to the west of the river; the only practical way to get a burden or a person down the Upsheer was on the right bank of the falls.

Which meant that Rigg, like everyone else lunatic enough to make a living bringing things down from the high country, would have to cross the river by jumping the ragged assortment of rocks just above the falls.

Once there had been a bridge here. In fact, there were ruins of several bridges, and Father had once used them as a test of Rigg’s reasoning. “See how the oldest bridge is far forward of the water, and much higher on the cliff wall? Then the bracing of a newer bridge is lower and closer, and the most recent bridge is only three fathoms beyond the falls? Why do you think they were built where they were?”

That question had taken Rigg four days to figure out, as they tramped through the mountainous land above the lake, laying traps. Rigg had been nine years old at the time, and Father had not yet taught him any serious landlore—in fact, this was the beginning of it. So Rigg was still proud that he had come up with the right answer.

“The lake used to be higher,” he finally guessed, “and the falls was also higher and farther out toward the face of Upsheer Cliff.”

“Why would you imagine such a thing as that?” asked Father. “The falls are many fathoms back from the cliff face; what makes you think that a waterfall can move from place to place?”

“The water eats away at the rock and sweeps it off the cliff,” said Rigg.

“Water that eats rock,” said Father. But now Rigg knew that he had got it right—Father was using his mock-puzzled voice.

“And when the lip of the cliff is eaten away,” Rigg went on, “then all the lake above where the new lip is, drains away.”

“That would be a lot of water each time,” said Father.

“A flood,” said Rigg. “But that’s why we don’t have a mountain of rocks at the base of the falls—each flood sweeps the boulders downstream.”

“Don’t forget that in falling from the cliff, the boulders shatter so the pieces are much smaller,” said Father.

“And the rocks we use for crossing at the top of the falls—they’re like that because the water is already eating down between the rocks, leaving them high and dry. But someday the water will undermine those rocks, too, and they’ll tip forward and tumble down the falls and break and get swept away, and there’ll be a new level for the falls, farther back and lower down.”