“Good work,” said Loaf.

“Rigg and Umbo just saved you from a terrible death,” said Olivenko.

The flyer took off.

“What, the mice were going to attack me?” asked Param, incredulous.

“Not by nibbling you to death, no,” said Olivenko.

“A cylinder of metal in the throat,” said Rigg. He demonstrated the size of it with his hands. “They slipped it into place during one of the gaps in your time-slicing. It tore your head off your body and burned you up.”

Param felt ill. “Why? What did I do?”

“I think they wanted to show us how easily we could be killed,” said Olivenko.

“I think they wanted to force us to use our powers and get out of here,” said Loaf.

“Why?” asked Param. “All they had to do was ask us to leave!”

“The people who wanted us to go may have been in the minority,” said Loaf. “We only ever met Swims-in-the-Air and Mouse-Breeder. It gave us an impression of perfect unity among the Odinfolders. But there may well have been a powerful faction that wanted us gone.”

“By killing me?”

“They knew we wouldn’t leave you dead,” said Rigg. “And they knew that we wouldn’t stay.”

“But what about meeting the Visitors?” asked Param. “I thought we were supposed to figure out a way to convince them not to wipe out Garden.”

“I don’t think so,” said Umbo. “I don’t think that was ever the plan.”

“They’ve been lying to us?”

“Of course they have,” said Loaf. “They’re only human.”

“Why did we believe them?” said Rigg, shaking his head. He imitated Swims-in-the-Air’s melodious voice. “‘We want you to figure things out yourselves. We want you to find your own way to convince the Visitors that we’re worth saving.’ Silbom’s right heel!”

“What did they want?”

“We don’t know yet,” said Loaf.

“I have a theory,” said Umbo.

“Which is?” asked Rigg.

“You’ll think it’s stupid,” said Umbo.

“Probably,” said Rigg. “But that doesn’t mean you won’t be right.”

“Or lead us to a right answer,” said Loaf.

“I think they’ve given up completely on changing the Visitors’ minds,” said Umbo. “I think they only wanted us to get on the Visitors’ starship long enough to smuggle a weapon aboard. A weapon that they’d carry back to Earth and wipe out the human race there before they can possibly send the Destroyers to kill all the people of Garden.”

“A weapon?” asked Param. “I thought we couldn’t build weapons.”

“Not literally a weapon,” said Umbo. “They can’t make a weapon. They haven’t made a weapon. Not mechanical, not biological, no such thing.”

“Then what is it that they’re supposedly going to smuggle back to Earth?” asked Rigg.

In reply, Umbo gestured toward Loaf.

Only now did Param notice that a couple of mice were perched on Loaf’s shoulders.

“Mice?” she asked.

“I told you there was no machine,” said Rigg. “But they think there is one. They think they’ve seen it, they think they know how it works. Instead, what they’ve seen is a very solid-seeming hologram. And when things get sent back in time and over to some distant location, they think the machine is doing it.”

Param realized what he was leading up to. “But it’s the mice doing it.”

“Mouse-Breeder’s mice,” said Umbo. “They have human genes in them. Including the genes of time manipulation. Only in these mice, the genes are expressed by time-displacement of inanimate objects. They can put anything anywhere.”

“So when they put a cylinder in my throat—”

“It’s what some Odinfolder humans told them to do,” said Umbo. “And they obeyed, because they knew that we could retrieve you.”

“Though it was harder than they thought,” said Rigg. “Because we didn’t want to retrieve you from a point before you learned all that you could learn here.”

“Whatever it is you learned,” said Olivenko. Was there a bit of scorn in his voice?

“We’ve spent nearly a year here, all told—a whole year since we left Ramfold and went to Vadeshfold. Which of the things that happened in that time should be erased?” asked Loaf. “We wanted to save your life, of course, but we didn’t want to kill a year of it in the process.”

Param felt uneasy, thinking of a version of the future in which her burnt-up body had no head left on it. “What will we do now?”

“Go to the border with Larfold,” said Rigg. “The wallfold to the north. Where Father Knosso was murdered.”

“We’re going to go back earlier and save him?” asked Param.

“We don’t dare,” said Umbo. “Not yet, anyway. We can’t go back before the time when Rigg took control of the Wall.”

“The flyer won’t pass through the Wall,” said Umbo. “We have to walk through. I’d rather not do it while experiencing the agony of the Wall.”

“We’ll go through the Wall at almost exactly the time Rigg took control,” said Loaf. “While we were still hiking around in Vadeshfold. Before we ever appeared here.”

“But they’ll see us,” said Param.

“Who?” asked Rigg.

“The Odinfolders.”

“Oh, well—they probably will,” said Rigg, “since they seem to cluster around the Wall. But they won’t know to stop us.”

“Unless the mice send them another Future Book,” said Umbo, laughing.

“Is that who’s been writing the Books of the Future?” asked Param.

“No, no,” said Olivenko. “This is the only timestream in which these mice existed. All the other Future Books were sent using the original crude displacement machine, before time-shifting was turned over to the mice and became precise.”

“And did the Odinfolders—the mice, I suppose—really alter Father’s genes? And create Umbo outright?”

“Yes,” said Rigg. “But this is the first timestream in which we existed. Ramex was carefully breeding for time-shifting power, but he hadn’t reached us yet, not until the mice intervened. And he would never have reached our level in his breeding program, because Garden would have been destroyed first.”

They explained to Param all that they had learned in the starship. And Param could see that something else had happened, too—Umbo and Rigg were still a little wary around each other, but Umbo was actually cooperating with Rigg and not arguing with every little thing he said. Something happened on that starship, and Param asked what it was.

“I died a couple of times,” said Umbo.

“Really?”

“Copies of me,” said Umbo. He explained how that worked, and Param nodded. “The way there must have been two versions of me back in the library, when we were running away a minute ago. Six months ago.”

“Only because your earlier self didn’t see your later self, and so you didn’t turn away from the path in which you time-shifted, you didn’t cause yourself to split,” said Olivenko.

“But I still died,” said Param.

“Only it’s all right,” said Umbo, “because we don’t remember dying.”

“It’s not all right,” said Rigg.

Param and Umbo both looked at him, waiting for an explanation, and Param was surprised to see how upset Rigg looked.

“It’s not all right, because I saw you both dead.” He looked away. “I never want to see that again.”

“Really gruesome?” asked Umbo.

“There was a version of both of you,” said Rigg, “that felt all the pain and terror of death. You don’t remember it, but it happened.”

“And by the Odinfolders’ account, the whole world has gone through that many times over,” said Olivenko.

“Which brings us back to Umbo’s idea,” said Param. “How do you figure the Odinfolders are going to destroy the human race on Earth, if they haven’t made a weapon or even planned what such a weapon might be?”

“The mice,” said Umbo, as if it were the most obvious thing in the world.

“What can they do?” asked Param.

“If a breeding pair can make it back to Earth,” said Umbo, “they’ll have maybe a dozen children after three weeks. If only five of them are females, and they reach sexual maturity in six weeks, and they have the same number of female children, five in a generation, how many will they have before that Destroyer fleet is scheduled to take off?”