Well, maybe she did, thought Rigg. Maybe she was learning some empathy for faceless ordinary unmet people. Most people never did, so she would be ahead of the game.

But it seemed to him that she was really still trying to justify the warning.

“We all made the same mistake,” said Rigg. “We leapt to conclusions and acted on them. Our conclusions weren’t stupid. They were partly right, but they were also partly wrong, and now we need to find out more of the truth so we can make better choices next time around.”

“Some choices can’t be unmade,” said Umbo. “You’ll have that facemask no matter what.”

And I’ll know that I’m a murderer, a killer who stabs his victim in the back, that won’t change either, thought Rigg. He said nothing of this thought aloud, however, or there’d be a new round of insistence that he was acting in self-defense, that even though the Ram Odin he killed hadn’t yet attempted to kill him, the Rigg who killed him had been attacked with intent to kill by the half-hour-later version of the man.

Enough of that. Enough of talk. Or rather, enough of old talk, and time for something new.

“The trouble with undoing the warning,” said Umbo, “is that I don’t want to lose some of the things I’ve learned since we gave it.”

Rigg’s first impulse was to say, You won’t lose anything. But then he realized the dilemma Umbo faced. He could not go back to a time after the warning and counteract its effects. He would have to go back before it, and prevent himself and Param from interfering with the mice getting on the Visitors’ flyer. All he’d really need is to give a warning, and his and Param’s earlier selves would not transport Param to give her message to the Visitors.

But then that would erase the future version of themselves, wouldn’t it? How many warnings had they given themselves, changing their own behavior so they never became the people who had given the warnings in the first place? And Umbo’s unspoken fear was that his new relationship with Param would be transformed.

Knowing Param, Rigg agreed completely. If Param, ready to be the agent who gave the warning to the Visitors, suddenly had Umbo tell her, No, my future self came back and warned me not to do it—it would frustrate her, disgust her. They would not come back to the beach as friends.

“Don’t do anything yet,” said Rigg. “You don’t really know if you were wrong. We don’t know why the Destroyers come; we only know that it has nothing to do with the man I killed. It still might be right to stop the mice. And even if it isn’t, there has to be another way to handle it. I don’t want you and Param to undo your lives like that.”

Umbo looked at him with such unconcealed gratitude and relief that Rigg was embarrassed. Who am I to be the judge and decision-maker?

But he knew what Father would say—what Loaf would say, for that matter, if Rigg laid out the case before either one of them. You didn’t decide a thing for Umbo. You merely confirmed him in the decision he already wanted to make. Your responsibility in the matter is very close to zero. Think no more about it.

Rigg had other things to think about. And yet there was nothing to think about at all. He had to go back and stop himself from killing Ram Odin, even though he knew the unavoidable result. He would have to live with that. When he and Umbo started fiddling with time, they hadn’t known the rules and weren’t responsible for the consequences. But they had learned the rules, or had learned a lot of them, anyway, and now Rigg understood well that not everything could be undone, or rather that undoing had consequences too, which you had to live with.

This time there was plenty of time for Rigg to say good-bye to the others. He explained to them what the facemask had done for him. How he could do what both Umbo and Param could do. “But don’t think this means that you should get facemasks of your own,” said Rigg. “We don’t yet know what Leaky will say when Loaf goes home.”

“Home,” said Loaf. “Like this?”

“Yes,” said Rigg. “You must go home. If this had come on you as the result of some horrible skin disease, she would stay with you. Let her choose for herself, Loaf. You know it’s what Leaky would insist on.”

Loaf grumbled and looked away. He had no argument—he knew that Rigg was right. Loaf was good at giving out wise-and-tough advice, but not so happy to receive it.

“Umbo will go with you,” said Rigg, “so that if things don’t work out right, he can help you try it again and again until it’s fine. And I think you should go back to a time soon after you left her the last time.”

“That’s before you opened up the Wall,” said Umbo.

In reply, Rigg handed him the jeweled knife. “Use the Larfold flyer to get to the Ramfold Wall, and then call the Ramfold flyer to take you back to Leaky’s Landing. It won’t be safe for you to go over land. Even if General Citizen isn’t looking for you, Loaf’s too pretty now to wander around in Stashiland without attracting a lot of attention.”

They agreed, even Umbo, without a hint of resentment. For once, they simply recognized that Rigg wasn’t giving orders, he was just stating the obvious.

No one asked, and Param didn’t volunteer, to say what she would do. If she went with them, she could take them back into the future. But if she stayed with her father in Larfold, she’d have no way of escaping back into the past next time the Destroyers came.

Whatever happened would happen. Umbo would make his way back to Param, or Param would decide to go with Umbo and Loaf. Olivenko would make his own decisions, too, and for all Rigg knew, Knosso and Olivenko would get Umbo to push them to some era far in the past, where they could live out their lives without any further complications or sudden ending of the world.

The group was breaking up. Maybe it would come back together. Maybe there would be some reconfiguration that would have Rigg in it. Rigg didn’t know.

What he knew was this: He could not live on with the knowledge that he had killed the wrong man. Loaf had said it long ago. It’s good to prevent a murder, but killing isn’t the only way. Rigg could stop Ram Odin from stabbing him in the back without going back and stabbing Ram Odin first. He had been so sure that Ram Odin was a monster that he never had the chance to find out if he was a man, or at least discover how he justified his lies and manipulations to himself.

Rigg got Umbo to call the flyer for him, and with a brief good-bye and a wave, he took off once again for the Wall. But now, without the knife, when he crossed the Wall he was on foot.

And that was how he wanted it. He went back in time a thousand years and traveled through the pristine wilderness of Vadeshfold. If Vadesh knew that he was there, so be it. Vadesh was a complicated machine, and knew far more than he ever told. But he had been right about the facemasks, and the people who extincted the human race in Vadeshfold had been mistaken, though their mistake was understandable. This symbiosis between mask and man was a good thing. Not for everyone; maybe only for a handful of people who were content to sacrifice their own eyes and ears to have these better, uglier ones put in their place. And maybe someday Rigg would get used to this terrible new face and not be frightened or saddened by his own reflection.

Today, though, each day, each hour of walking through the forest, trapping an animal now and then when need arose, but mostly living lightly, working off the little bit of adiposity that life in Odinfold had given him, Rigg was as happy as he had ever been since Father “died.” Yes, he was alone, but he needed to be alone; until now, he had not really understood how painful and heavy it was to have the needs of others always in his heart and on his mind.

I have only my own need now—to unmake my crime and see if that will clean my soul.