“So you’ve already thought about this?” asked Rigg.

“Just keep peeing,” said Umbo.

By the time they were through, Loaf was back.

Umbo asked, “Where did you go?”

“Shut up,” replied Loaf. “What now? What’s this all about?”

“Rigg and I decided that whatever it is, it’s probably not the worst thing in the world. I mean, we know that you and I are still alive, whatever happens to Rigg.”

“I thought I told you to shut up,” said Loaf, sounding more like he meant it now.

They showed their three-person pass to a different set of guards from the ones Loaf had talked to before, so they wouldn’t see Rigg’s rich-boy clothing and decide they had been defrauded of their rightful bribe. Then they joined the throng of pilgrims going in.

Though the outside was metal, inside the structure was massive stone, with a long narrow ramp climbing in a spiral up the inside walls. There wasn’t a window in the place, and yet it was brightly lighted by magical globes hanging in the air.

“This ramp is steep,” said Loaf.

“You’re getting old,” said Umbo. “I could run all the way up.”

“Do it then,” said Loaf.

“No,” said Rigg. “The ramp is narrow, and all it takes is one pilgrim getting irritated and giving you a shove.”

“But I can’t die,” said Umbo. “Because I’m alive in the future to come back and warn you to do whatever.”

“Maybe you came back from the dead,” said Rigg.

“Come on, that’s impossible,” said Umbo.

“Coming back from the future is impossible, too,” said Loaf. “If you can explain one, you can explain the other.”

Rigg wasn’t at all sure he could explain anything, at least not well enough to be sure Loaf would believe it. After all the years Father had pressed on him the importance of telling no one, he had no practice in explaining anything to anyone. Nox already knew, and Umbo had a gift of his own. Yet to tell Loaf less than everything now was to make it plain that he was not trusted. That would make him resentful—and therefore less trustworthy. If future-Umbo thought it was safe to trust Loaf with the jewels, it seemed pointless not to include him in the secret of their shared power to reach backward in time.

All the other pilgrims on the ramp ahead and behind them were engaged in their own conversations. Keeping their voices at a normal volume, Rigg and Umbo told him about their abilities, and what they were able to do together. Between Loaf’s questions and Rigg and Umbo correcting each other, it soon was clear enough.

“You still have that knife?” asked Loaf. “It didn’t disappear or anything, did it?”

“In my luggage,” said Rigg.

“Well, not actually,” said Umbo.

Rigg sighed. “What, future-you came back in time to tell you to take it and put it in your own luggage?”

“Loaf’s luggage, actually,” said Umbo.

“I was joking,” said Rigg. “Are you telling me you already knew that some future version of you was paying social calls on us?”

“He—I—woke me up this morning and told me to do it and then disappeared before I could ask any questions. I think me-in-the-future isn’t very good at it and a few seconds were all I could manage. Anyway, I didn’t tell you because why would you believe that I wasn’t just stealing it? Then you got your warning and it seemed way more important than mine. I mean, that’s a fortune in jewels, and you gave it right to Loaf.”

“And if he had told you he took your knife, would you have trusted him when he told you to give me the jewels?” asked Loaf.

“Yes,” said Rigg. “Probably.” He thought a little more. “Maybe not.”

“I think he handled it right,” said Loaf. “Unless he is stealing stuff, but then why would he have you give the jewels to me, and put the knife in my luggage? No, I think whatever happens will make it so I’m the only one who doesn’t lose all my stuff.”

“What could make us lose our stuff?” asked Rigg.

“If the boat sinks,” said Umbo, “Loaf would lose his stuff, too.”

“If the boat sinks we all drown,” said Loaf.

“I can swim,” said Umbo. “So can Rigg. Like fish. Can’t you?”

“I’m a soldier. I was always wearing armor, I would have sunk right to the bottom. And since then why would I learn to swim?”

“It’s a useful skill,” said Umbo. “Especially for people who live by the river and might get tossed in by rivermen.”

“Most rivermen can’t swim either,” said Loaf.

“You still haven’t answered,” said Rigg. “Can you swim?”

“The idea is to stay in the boat,” said Loaf.

“Try again,” said Rigg.

“If you never admit you can swim,” said Loaf, “people think they can kill you by throwing you in the water.”

“Look,” said Umbo.

They had finally climbed up just higher than the balls of light and now the glare no longer prevented them from seeing the upper half of the tower. They could see that the stone ended not far above them, with a wide porch that ran all the way around the inside of the tower. It was crowded with pilgrims.

“Keep moving,” said a gruff man behind them. They walked on.

But glances upward told Rigg that from the platform ring, more than a dozen stone pillars rose to form vertical ribs that supported the metal walls. He remembered observing outside the Tower of O that from about the middle, the metal shell tapered in. So he was not surprised that the stone pillars leaned inward, right up against the metal, until the pillars were joined together by a metal-and-stone ring high above them. Beyond that, the metal formed a simple dome with no stone supporting it at all.

It was a marvel of engineering and design, making the stone support its own weight, and then the weight of the metal. It occurred to Rigg that the metal must be very, very thin, or it would be too heavy for the stone to support.

They got to the platform and moved far from the upward ramp. The beginning of the downward ramp was on the opposite side, and between them, hanging in the air, was an enormous ball. The globes from below and fewer globes from above lighted the entire surface of it. Now, though, they could see that wires from the top ring supported the globes of light, and probably there was some wire arrangement supporting the bigger ball.

The surface was painted in a way that Rigg did not understand. It didn’t seem to be a picture of anything, and the colors were drab and ugly and didn’t go together. There were brighter yellow lines making divisions on the largest areas of green and brown, and those seemed to shine. But the pattern of them made no sense. Perhaps a honeycomb made by drunken bees?

“There’s the world,” said Umbo. “It’s a picture of the world right there.”

Umbo was pointing to a particular place on the surface of the big globe. “See? That spot of red, that’s where Aressa Sessamo is. And that white spot, that’s O. The blue line is the Stashik River. So Fall Ford would be a little lower down.”

“Then the yellow lines are the Wall,” said Loaf. “I’ve patrolled the Wall, and that looks about right. But what’s the rest of it?”

“The whole world,” said Rigg, understanding it now. “It’s a globe, round in every direction, just like this.”

“Everybody knows that,” said Loaf. “Even the most ignorant privicks.”

“That’s crazy!” said Umbo, in mock dismay. “We’d all fall off!”

Rigg made a joke of explaining it to him, as if to a little boy. “No, no, little Umbo, the center of the world pulls on us, holding us to the surface. ‘Down’ is really toward the center.”

“This map of the globe is impossible,” said Loaf. “Nobody knows what’s outside the Wall. No one in the whole history of the human race has passed through it to see.”

“But you can see through it, right?” said Rigg.

“Not far enough to know things as distant as this map shows. Not just the neighboring wallfolds, but all of them. If it’s a map.”

“It’s a map,” said Umbo. “Come on, it can’t just be random chance that they show the course of the river and O is a white dot and the capital is a red dot.”