“I’m not going to marry Umbo or have his babies,” said Param.

“I didn’t suggest that you do so,” said Olivenko. “I said he would take you back in time. You’re the one who leapt to the conclusion that Umbo would be involved in any marriage or baby-making you might embark on.”

Umbo spoke from the other side of the fire, where he had been dozing. “Thank you for finding a way to insult me in a conversation I wasn’t even part of.”

“I’m not having your babies or Olivenko’s,” said Param. “Or Loaf’s, in case anyone wants to include him. The world is ending no matter what time period we go back to. So what if it’s twenty years or two hundred? Knowing the whole world burns makes the whole enterprise . . .”

“The whole world always burns,” said Loaf. “Or it floods. Or some insect eats the crop and you starve. Or a disease ravages the wallfold, killing nine out of ten, and the survivors eat the dead. Every baby you have dies eventually, no matter what you do. Yet we have babies and we try to go on.”

“I’m not sure,” said Umbo. “Is that your idea of inspiring us with new hope?”

“It’s my way of telling you that only a child thinks that anything you build will last,” said Loaf.

“What we’re waiting for,” said Olivenko, “and we all know it, is Rigg.”

Since they all knew it, there was no point in commenting.

Umbo commented anyway. “He could have returned to us at any time. For instance, a half hour after he left, he could have walked back into our camp and told us what he had just spent the last week or month or five years doing. When somebody can jump from one time to another, it’s just rude to make other people wait.”

Nobody said anything.

“That was not just me being resentful of Rigg the way I used to be,” said Umbo into the silence.

“Nobody said it was,” said Olivenko.

“I’m just tired of waiting,” said Umbo. “And it is rude of him.”

“On the other hand, maybe he’s dead,” said Loaf. “In which case, our wait is truly pointless.”

“Who could possibly kill Rigg?” asked Param. “He already stopped Ram Odin from assassinating him.”

“And now he’s gone back to stop himself from stopping Ram Odin,” said Loaf. “Which means Ram Odin might still find a way to kill him.”

“Even with the mask?” asked Olivenko.

“He won’t try to kill me again,” said Rigg.

If anyone was startled by his sudden appearance, they didn’t show it. Umbo had to laugh, though. “How many times did you make a later entrance till you decided on this moment?”

“I came, I heard, I answered,” said Rigg. “I don’t have to time my entrances. You’re always arguing, and there’s always something to say that’s smarter than anything you’d come up with.”

“Good to have you back,” said Param. “To remind me that Umbo isn’t the only annoying boy in the world.”

“So Ram Odin is alive again,” said Loaf.

Rigg nodded.

“Is that a good thing or a bad?” asked Olivenko.

“Decide for yourselves,” said Rigg. “Because the way I fixed it resulted in more than saving Ram Odin.”

He raised a hand. Immediately two others emerged from the edge of the woods and came to stand beside him. An old man and . . . another copy of Rigg, facemask and all.

“This is so untidy,” said Umbo.

“Says the one who made two copies of himself already,” said Rigg.

“At least my copies are dead,” said Umbo.

“And mine is alive,” said Rigg. “He has chosen the name Noxon, so you’ll have a way to speak of us separately. But in a way, he’s a purer version of myself. He never killed anybody.”

“But I would have,” said Noxon.

“But you didn’t,” said Rigg.

“The Rigg twins even argue with each other,” said Loaf.

“Rigg probably had arguments with himself all the time,” said Olivenko.

“But we didn’t have to overhear them,” said Loaf.

“So you’re the one who planned all this,” said Param to Ram Odin.

“I’m the one who made decisions when they had to be made,” said Ram Odin. “Sometimes good ones, sometimes bad. Most of the important decisions were made by someone else. But I accept responsibility for what I’ve done wrong. For things I’ve unleashed on the world. Like the mice. And, in a way, the three of you. Four of you now. The timeshapers.”

“Look how happy he is,” said Loaf. “Almost quivering with excitement. After studying you remotely all these years, he finally gets to meet you face to face.”

“Quivering?” asked Ram.

Noxon answered him. “It’s a subtle vibration,” he said, “but the facemask makes it as obvious as breaking into a jig.”

Umbo could not understand why having two Riggs made him so angry. Was it his old envy coming back? Was he so foolish as to be jealous because there was only one of him? Or frightened because now there were two timeshapers more powerful than him and Param? “I’m glad you were able to undo the killing,” said Umbo. “What now?”

Rigg shrugged. But Noxon answered, “I know what I’m thinking of doing, but I can’t decide for anyone else.”

Umbo thought: The two Riggs have already diverged.

Or maybe it was just that Rigg, the one who had killed Ram Odin, was stricken silent by Umbo’s reference to undoing his “killing,” while it meant far less to Noxon, who had no memory of the deed.

“So . . . are you going to tell us?” asked Olivenko.

“I’m going to Earth,” said Noxon. “If I can master the skills it will take to get there. Because I’m not going with the Visitors. I’m going back eleven thousand years and hitching a ride on the twentieth starship, backward in time.”

“If it exists,” said Umbo. “It’s only a mathematical guess.”

“If he can learn to reverse his direction in time,” said Rigg. “To hook on to something moving the other way.”

“I’m thinking that Param and I might be able to help each other learn some new skills,” said Noxon.

“I can’t help anybody,” said Param. “My talent is almost worse than having none at all.”

“No it isn’t,” said Olivenko.

“Mother made sure my enemies know how slowly I move,” said Param, “and how vulnerable I am when I’m invisible. The mice know it, too. It used to be I could always get away from anyone who tormented me. But now, it only makes me weaker.”

“That’s how I think we can help each other,” said Noxon. “I need to learn how to slice time—how to match the rhythm and duration of each increment. It’s become second nature to you. I’m not as sharp as Umbo—he learned how to jump without me way faster than I learned how to jump without him.”

“And what will you teach me?” asked Param.

“How to do it backward,” said Noxon. “Because that’s the direction I need to move, too.”

Param shook her head. “I skip time, I don’t change directions.”

“That’s my point,” said Noxon. “What if, when you disappeared, you could slice your way backward in time? When Umbo and I . . . and Rigg . . . when we jump in time, we skip over everything in between. I . . . and Rigg . . . we can see the paths, and the facemask lets us see them as people in motion. Extending backward in time. But they’re always moving forward. So when I attach to them, I attach in the direction they’re going. I need to know how to go upstream. How to slide backward in small increments, and you need to learn the same. I’m hoping we can help each other.”

Param shook her head again. “I can’t do anything like that.”

“We know you can’t,” said Rigg. “That’s what ‘learning’ means. Now you can’t; with work, maybe someday you can.”

“And what will you be doing while Noxon and Param are working on doing new impossible things?” Olivenko asked Rigg.

“I’m planning to go through the other wallfolds, one at a time, and see what they have. We’ve seen Ramfold, Vadeshfold, Odinfold, and Larfold. Fifteen to go.”

“And then what?” asked Olivenko.