the shift is red. The computers are having a very hard time coping with the contradictory data.”
“Compare the degree of red shift with the red shift when we were in the same position on our way to the fold.”
The expendable didn’t even pause. It was a simple data lookup, and to a human mind it seemed to take no time at all.
“The red shift is identical to what was recorded on the outbound voyage.”
“Then we are simply repeating the outbound voyage,” said Ram. “The ship is moving forward, as propelled by the drive. But we, inside the ship, are moving backward in time.”
“Then why are we not observing ourselves as we were two days ago on the outbound voyage?” asked the expendable.
“Because that version of ourselves is not moving through time in the same direction as we are,” said Ram.
“You say this as if it made sense.”
“If I started crying and screaming, you’d stop taking me seriously.”
“I’m already not taking you seriously,” said the expendable. “My programming requires that I keep your most recent statements in the pending folder, because they cannot be reconciled with the data.”
“It’s really quite elegant,” said Ram. “The ship is the same ship. Everything about it that does not need to change remains exactly as it was on the outbound voyage. It occupies the same space and the same time. But the flow of electrical data and instructions through the computers and your robot brain and my human one, and our physical motions through space, are not the same, because our causality is moving in a different direction. We are moving through the same space as our earlier selves, but we are not on the same timestream, and therefore we are invisible to each other.”
“This is an impossible explanation,” said the expendable.
“Come up with a better one, then.”
This time the expendable waited a long time. He remained completely still while Ram deliberately and without hunger pushed food into his mouth and chewed it and swallowed it.
“I do not have a better explanation,” said the expendable. “I can only reason from information that has already been reasoned from successfully.”
“Then I suppose that’s why you needed a human being to be awake after the jump,” said Ram.
“Ram,” said the expendable. “What will happen to us when this ship reaches Earth?”
“At some point,” said Ram, “either the two versions of the ship will separate and probably explode, or we will separate from the ship and die in the cold of space, or we will simply reach Earth and continue to live backward until I die of old age.”
“But I am designed to last forever,” said the expendable, “if not interfered with.”
“Isn’t that nice? Expendable yet eternal. You’ll be able to go back and observe any part of human history that you wish. Watch the pyramids being unbuilt. See the ice ages go and come in reverse. Watch the de-extinction of the dinosaurs as a meteor leaps out of the Gulf of Mexico.”
“I will have no useful task. I will not be able to help the human race in any way. My existence will have no meaning after you are dead.”
“Now you know how humans feel all the time.” • • • They were at the docks, all their new clothes packed and the trunks ready to be loaded onto a much better grade of boat, when Rigg looked back at the city of O. From here, he could barely see the tops of the white stone buildings over the ramble of houses and warehouses near the wharf. But he remembered what he would see again as the boat pulled farther and farther from O.
“We’d be fools, wouldn’t we,” said Rigg, “if we spent these weeks in O and never visited the tower.”
“That’s what I thought,” said Loaf. “But you were determined to go as soon as the money came in.”
Rigg wanted to say: Then why didn’t you advise me to see it? But then he remembered two things: First, Loaf had said, in a hinty kind of way, things like, “All these pilgrims heading for the tower-what do they care for the city?” and “People live here in O all their lives and never visit the tower.” This was not at all the forceful way Loaf used to give advice, so Rigg didn’t hear it as counsel, he heard it as mockery of the pilgrims and the locals.
And second, this was exactly the kind of change that Rigg dared not criticize for fear of making it worse. Loaf was treating him now the way he treated wealthy customers who by some bit of ill-fortune were reduced to stopping at his tavern. Deference bordering on cringing was the order of the day-Rigg saw it in the people who served him in his lodging house, and he saw it in Loaf as well, a side of him that had never surfaced before, not even when he and Leaky found the jewels.
They had known they were worth a lot of money, but had not been able to conceive how much; nor had they really believed that Rigg was capable of holding on to his wealth. Hadn’t Loaf come along precisely so Rigg would not be cheated? He had said more than once, “Looks like I wasn’t needed after all, you handled them just fine,” and each time Rigg would reassure him that without Loaf there, no one would have taken Rigg seriously at all-he would have lost everything as soon as someone reached out to take it. “I’m not a fighter, Loaf-you are. So they’d look at you, and then they had to listen to me.”
But Loaf only believed it for a moment, if at all. He was in awe of the negotiating skill Rigg had shown. “You sounded like an officer,” he had said.
Well, if sergeants gave such limp, irresolute advice to their officers, it’s a wonder anybody ever won a battle!
So Rigg made no argument with Loaf’s mild I-told-you-so. “You did say it was worth seeing, didn’t you,” said Rigg. “Well, let’s see it now.”
It took only a wave of the hand to have a coachman bowing to Loaf, who was still as forceful as ever when dealing with people he regarded as his equal or lower. In a minute Rigg, Umbo, and Loaf were inside a coach, their luggage left in the care of the boat’s captain.
It took two hours to get to the Tower of O-one hour to get through a mile of maze-like streets leading to the nearest city gate, and the second hour to go the five miles along the road to reach the base of the tower. The road they took was really the cleared area outside the city wall, intended to force an enemy to come uphill, fully exposed to projectiles from the defenders of the city, so they stayed so close to the wall that they could not see the tower at all until suddenly they rounded a bend and there it was, looming over them, looking as tall as Upsheer Cliff.
“But it’s not as tall,” said Umbo, when Rigg said so. “We’re two miles away, and the cliffs don’t look like that until you’re five miles back.”
“It’s the tallest thing I’ve ever seen,” said Loaf.
“You need to come upriver more,” said Umbo. “Become a true privick.”
“The ambition of my life,” said Loaf.
The stream of pilgrims coming and going made it impossible to bring the coach as close as they might have wished. “Just as well,” said Loaf. “You need to let me and Umbo go ahead and make our offering for three people, or the keepers of the tower will get one look at you and triple the price. Or more.”
“Then I’ll pay the coachman-I’ll pay him enough to wait for us. How long does it take in there?”
“Never long enough,” said Loaf.
“Enough for what?”
“To see it all, or understand what you’re seeing,” said Loaf.
Loaf and Umbo alit from the carriage-that is, Loaf stepped and Umbo fairly leapt from it and ran on ahead. Rigg talked to the coachman, who kept saying, “I’ll be here waiting, young master, see if I’m not,” and Rigg kept saying, “But let’s agree on a price or you’ll think I cheated you,” not adding “or vice versa,” and the coachman would reply, “Oh, young master is generous, I seed that right away, I trust in young master’s generosity,” which was enough to make Rigg crazy. He looked over and in the near distance saw Loaf and Umbo talking to one of the extravagantly uniformed tower guards, and wondered if they were having half the trouble he was having getting a price set.
As he stood there, gazing at his friends, he heard a voice at his side. Umbo’s voice. And he was speaking so rapidly that Rigg couldn’t understand him.
Rigg turned to face him, then glanced back at where he could see Umbo right beside Loaf. The two Umbos were dressed differently, and the Umbo standing beside him looked distressed, frightened, and deadly serious. Rigg knew at once what was happening. Somehow a future version of Umbo had managed to learn the trick of
