“A few. Mostly tiny ones above Upsheer,” said Rigg.

“Hardly anybody,” said Umbo. “So that means there could be hundreds like your father, and you wouldn’t know it.”

“Father would have told me,” said Rigg.

“Unless he thought it wasn’t good for you to know,” said Umbo.

Rigg had to admit, that was the truth.

At last they reached the bottom and passed through the entrance of the tower into the bright noon sunlight. It had taken at least an hour to get up, and almost as long to get down, and despite all the things they said and observed up in the tower, they hadn’t been there all that long.

“They’re checking people,” said Rigg.

He only noticed it because he saw the converging paths of many guards—people who were not part of the general flow of pilgrims to and from the tower. There was a choke point, and they were heading for it. Rigg felt the dread from future-Umbo’s warning come to the surface. “They’re looking for someone,” he said.

“That’s why they check people,” said Loaf.

“Separate from us,” Rigg said to Loaf.

“No,” said Loaf.

“There are too many guards, you couldn’t fight them. We need you to stay free. That’s why Umbo warned us to give things to you, don’t you see? Separate from us. Drift back, don’t make a sudden movement the wrong way.”

“I know how to do it, thank you, boy,” said Loaf. And he began to walk a little faster, drifting forward through the crowd. As he went, he took off his outer jacket and carried it, tucking his hat under the jacket as well.

Rigg was pleased to find out that his instinct had been the same as a soldier’s knowledge.

But after a while, Loaf drifted back to them. “It’s Cooper, the banker,” said Loaf. “He’ll know my face.”

“Cooper?” asked Rigg.

“There are two officers of the People’s Army with him, letting him look at everybody who passes. One of the officers is very high, a general I’m sure.”

“I thought the People’s Army had no ranks,” said Umbo.

“They have no insignias of rank,” said Loaf dismissively. “But a general is a general. Look, Rigg, if Cooper hadn’t been scrutinizing all the nearer faces, he would have seen me—I was in plain view.”

“Maybe he’s looking for someone else,” said Umbo.

But Rigg knew that for some reason, on some pretext, Cooper had betrayed them. “Go back into the Tower of O and wait for a couple of hours.”

“Cooper will just tell them to look for me inside,” said Loaf.

“No,” said Rigg. “We’ll tell them you left us hours ago because you were tired and didn’t want to climb. Do you have the money?”

“Most of it. But they’ll still search my luggage,” said Loaf.

“I’ll try to get them to turn Umbo loose, too,” said Rigg. “I’m the one Cooper wants.”

“How do you know that?”

“Because I’m the one who owns the money,” said Rigg. “I should have known it was too good to be true.”

Umbo spoke up, his face reddening. “Loaf, I didn’t put the knife in your luggage.”

“Why not?” asked Rigg.

“Where did you put it?” asked Loaf.

“Behind a barrel of salt pork in the boat’s galley,” said Umbo.

“Got it,” said Loaf. Then he drifted back in the queue, made a show of looking for something, and then went back against the flow of the crowd, ostensibly to find it.

“Why did you lie about the knife?” asked Rigg, as he and Umbo continued forward toward the checkpoint.

“I told you I put it in Loaf’s bags so you wouldn’t think I was trying to steal it. You even said yourself that you wouldn’t trust me if you thought I was stealing.”

“Umbo,” said Rigg, “I was wrong when I said I wouldn’t trust you. I trust you with my life.”

Umbo said nothing.

Rigg tried to keep other people between him and Cooper—he wanted to give Loaf plenty of time to get back inside the tower.

“Father always accused me of the worst thing,” said Umbo. “Whatever it was, he always said I was planning to do it. I’m just . . . used to it.”

“We’re friends, Umbo,” said Rigg. “Now try to act stupid and confused.”

“That won’t be acting,” said Umbo.

“I’m going to try to get you out of this,” said Rigg.

Then the people in front moved quickly forward and Rigg was staring Cooper in the face.

“That’s him,” said Cooper. “That’s the boy who’s claiming to be a prince.”

CHAPTER 9

Umbo

“If we are trapped inside the same starship, Ram, on the same voyage, moving backwards through time,” said the expendable, “why did the ship’s computers show that we made the jump successfully?”

“What were the criteria for determining a successful jump?” asked Ram.

“Observations of the positions of distant stars relative to how they should look near the target star system.”

“Can you bring up an image of what the stars looked like at the moment the computers determined that the jump was successful?”

In an instant, a hologram of a starfield appeared in the air over Ram’s console.

“I take it that’s not the appearance of the stars around our present position.”

“Correct,” said the expendable.

“How long did the stars have the appearance recorded here?”

“The scan was repeated three nanoseconds later and the stars were as they had been just before the jump.”

“So we made the jump, and then we unjumped,” said Ram.

“So it seems.”

“And we’re sure that this wasn’t just a glitch? That the computers weren’t just ‘detecting’ what they were predicted to detect?”

“No, because the starfield of the target was not quite identical to the prediction.”

“Show me the difference,” said Ram.

The starfield view on his holodisplay changed to show yellow and green dots instead of white ones.

“The nearest stars show the most difference, and the farthest ones the least,” Ram observed.

“Not always,” said the expendable, pointing to the few exceptions. “This is expected because our observations of the universe are based on old data—light that has had to travel ninety lightyears to reach Earth.”

“Didn’t the astronomers allow for that?”

“Yes,” said the expendable. “But it was partly guesswork.”

“Let’s play a game,” said Ram. “What if the difference between the prediction and what was observed in that less-than-three-nanosecond interval could be explained, not by astronomer error, but by the passage of time. Is there some point in the future or in the past when the stars would be in these positions relative to the target star system?”

One second. Two seconds.

“Eleven thousand years ago, roughly speaking,” said the expendable.

“So when we made our jump through a stuttering, quantized fold in spacetime, the fold didn’t just move us through space, it also moved us backward in time.”

“That is one explanation,” said the expendable.

“And so we got hurtled back into our previous position in spacetime, only progressing backward.”

“So it would seem,” said the expendable.

“That must have taken enormous energy,” said Ram. “To move us eleven thousand years backward in history, and then to recoil back to the present while reversing the flow of time.”

“It might have,” said the expendable, “if we understood how this actually works.”

“Please tell the computers to calculate what laws of physics would explain an exactly equal expenditure of energy for the two operations—passing through the fold into the past, and passing back but reversing direction.”

•  •  •

Umbo tried not to glare at Cooper. Stupid and confused, that’s how he was supposed to act. So he stared at the officers. Loaf had been right—the one with the more rumpled-looking uniform was showing nothing on his face, but there was something about his posture, the tilt of his head, that suggested he expected to be noticed and obeyed.