You think you know where you are, you think you know what’s what, and suddenly nothing is the way you thought, and it should have been obvious all along, and you feel stupid for having made assumptions, and you were stupid, but . . . Umbo could hear Wandering Man say, “It isn’t stupid when you assume things; that’s how the human brain is supposed to work. We assume things so we can act much more quickly than animals that only see what they see.”

Act quickly, yes, but wrongly if you assume wrong, Umbo thought both then and now. But he had said nothing, because he was so awed to be spending a few moments with Rigg’s strange and wonderful father. The machine.

Umbo moved across the narrow part of the wood, wading through leaves rather noisily, as if they were another kind of stream. Finally he got to lawn again, and now the city loomed on his left, farther away than the trees on his right, but much taller. Umbo stood looking at the buildings, wondering where the people went, and whether Vadesh stood in one of the towers, looking out and down at him.

Umbo wondered if Vadesh wondered about anything. Neither Vadesh nor Ram ever seemed uncertain. Even when they said they were uncertain, they sounded certain about it. Umbo didn’t even know when he didn’t know what he needed to know.

Vadesh had said that he couldn’t predict the future with any certainty. He had known a billion things that the humans from Earth might do when and if they arrived here on the planet Garden, but he did not know what they would do, he said. Well, didn’t that imply that he didn’t know what Umbo and the others would do, either? That was something for Vadesh to wonder about.

We are unpredictable to him, thought Umbo. The thought made him vaguely happy. He is manipulating us, deceiving us, withholding information from us, precisely because he doesn’t know what we’ll do and he wants us to do some particular thing.

That’s the key to this whole thing. He needs us, and so he has to manipulate us into doing a thing that is so important that it’s more important than telling us the truth. Why doesn’t he just tell us what he wants? Because he doesn’t know if we’ll do it knowingly. Or maybe he’s quite sure we won’t do it knowingly, and so he has to trick us or lead us into a situation where we have no choice but to do what he wants.

The way Rigg got us right up against the Wall.

Only Rigg is a good guy and didn’t think he was manipulating us to do his will.

Or maybe he did manipulate us on purpose, and I don’t really know him at all.

Umbo rocked his head forward and touched his fingers to his forehead. I keep coming back to not liking or trusting Rigg. Maybe that’s what Vadesh wants.

He heard Param coming. He knew it was her from the lightness of her step. “It’s not your watch yet,” he said. “I only just started.”

She kept coming. “You’ve been walking around for an hour or so,” she said. “If I’m any judge of time.”

“In this group,” said Umbo, “who can trust time to be the same from minute to minute?”

“I couldn’t sleep,” said Param. And then, incredibly, she put her arm through Umbo’s and stood close to him. She was warm. Umbo shivered.

“You’re cold,” she said.

“Not now,” said Umbo. Then he realized that his words might sound like he was being flirty and so he corrected himself. “I mean, I was really cold a while ago when I stepped in a wet place down by the brook—”

“You went down to the water?” she asked, incredulous.

“Not on purpose,” said Umbo. “It was a boggy place—”

“You could have—”

“I wiped down my legs and feet and there was nothing.”

“But he said they were really small in the water—”

How could he argue with her? Why should he try? “If I stepped into a boggy spot and picked up a facemask parasite then it’s done, and I can tell you what it feels like.”

“As it takes over your brain,” said Param.

“Nobody’s been using it anyway,” said Umbo. He meant it to sound jocular. Instead it sounded self-pitying.

But Param didn’t rush to reassure him, which would have made him seem even more pathetic to himself. “Maybe you and Barbfeather can talk to each other.”

“Maybe we’ll look really pretty to each other,” said Umbo. “Just my luck to find a best chum who has four legs and can’t talk.”

“Four-legged untalking people make the most reliable friends,” said Param. Was there bitterness in her voice?

“I can see you’ve never tried to befriend a cat.”

“I was forgetting cats.” She leaned her head on his shoulder. “I can understand why Rigg helped me, back in the capital. He’s my brother. But you—you sat there with me on that rock, holding the others back in that ancient time until Mother’s soldiers were almost on us. And Rigg and Loaf and Olivenko aren’t your kin or anything.”

“Rigg is more my friend than any of my kin,” said Umbo.

“If Rigg hadn’t signaled you to bring him back to the present . . .”

“Then I would have kept him in the past until he did.”

“You weren’t worried that they’d kill you?”

“Of course I was. If they killed me, then I couldn’t have brought them back,” said Umbo.

“What about me?” asked Param.

Umbo shook his head. “See how gallant I’m not? I knew you could take care of yourself.”

“I knew you were in danger. I kept wanting to grab you and make you disappear. But if I did, that might have been the same as killing the others.”

“But you took me away the moment I brought them back to the present,” said Umbo.

“All I could think was, get him off this rock,” she said.

“You saved my life.”

“I almost got us both killed,” she said, shuddering. “I let Mother and the soldiers see which way we jumped. They’d know we couldn’t change direction in midair. So if you hadn’t pushed us back a week—”

“But I did.”

“I jumped without thinking.”

“You had no other choice. You kept us alive in that moment.”

“And then you kept us alive in the next.”

“So on the whole, I think we saved each other,” said Umbo. Then, on a whim, he pulled away far enough that he could turn to face her and make a joke. “My hero,” he said.

Only she must have had the same idea for the same joke, because at the exact same moment she said, “My hero.”

But she wasn’t sarcastic. Or maybe her sarcasm was so thick that it sounded like sincerity.

Well, either she was joking or not. All Umbo could do was react the way he would to either. “Don’t count on its happening again,” he said. “I’m not really the hero type.”

She playfully slapped his face—just a tap with a few fingers. “Can’t let somebody thank you, is that it?”

At the moment, all Umbo could think was—well, nothing, really, because he was beyond thinking. She had taken his arm and leaned close against him, she had bantered with him, thanked him, praised him. Called him her hero, even if it was kind of a joke. And now she was teasing him. He was in heaven. And yet he was also totally focused on everything she said and did so that he could respond.

“Thank me all you want,” he said. “As long as I can thank you back.”

“One of the best things about finding out I have a brother,” said Param, “is that I inherit all his friends.”

Friends. That’s what they were. She was teasing him like a friend.

“Which is a lot more than I’ll ever inherit from my mother,” said Param ruefully. She turned back to look at the city. “I think that place is so sad. So glorious, and yet they left it behind. All that work, all that marvel, and they walked away.”

“Maybe they ran,” said Umbo. “Maybe they died.”

“Well, they’re all dead by now,” said Param. “I remember being so distraught when Papa died. I wasn’t there to watch, the way Olivenko was, but I loved him more than anybody. And Mother took me by the shoulders and said, ‘Everybody dies, and since we don’t all die at once, somebody’s always left behind. Just be glad it wasn’t you who died.’ I should have realized then what Mother was. Or maybe I did. She was perfect—perfectly selfish. Well, no. Perfectly devoted to the Tent of Light. She had seemed so devoted to me. But I knew then that if I died she’d feel exactly what she felt about Father’s death.”