Bleht thougt about this for a while. So did Olivenko.

It was Olivenko who spoke. “I remember he said, ‘We did it.’ There, looking at the timeline, he said ‘we did it’ and I thought he meant that we—he and I—had just done something. But he might have meant that we, the human race, did ‘it’—the making of the Wall.”

“I can see why neither of you will ever be a real scholar,” said Bleht. “You both leap to conclusions.”

“Good scientists always leap to conclusions,” said Rigg. “What makes them scientists is that they doubt those conclusions and try to disprove them. Only when they fail to disprove them do they start to believe them.”

Olivenko nodded. Bleht snorted again. “You sound like you’re quoting someone.”

“I am,” said Rigg. “My father—the one who raised me.”

“Well, while you’re leaping to conclusions, young non-prince,” said Bleht, “explain this: Even if humans could possibly create something like the invisible, impenetrable Walls that surround our wallfold, why would they do it?”

“That,” said Rigg with a smile, “is a historical question.”

A ghost of a smile passed across Bleht’s face, as if to say, Well answered, boy.

“Whatever killed Father Knosso,” said Ovilenko, “was not human.”

“So maybe the Walls divide the world among species?” asked Rigg. “Maybe the home world had also been divided?”

“Maybe the Walls exist to keep a state of war from existing between us and the sea people who killed Father Knosso,” said Ovilenko.

“What a lovely game of guesses you two lads are playing. But it’s not a spectator sport.” Bleht rose to her feet.

Rigg spoke at once, trying to hold her. “Father said that our name for the world is one of the oldest, and every language in the wallfold has a form of it.”

Bleht waited to hear the rest.

“He didn’t tell me what the original language was, but he said the word and then told me it meant ‘Garden.’ I’ve thought of it as Garden ever since.”

“And the significance of this supposed original meaning of the name?”

“Our world—this world—this world with a ring instead of a moon—”

“What’s a moon?” asked Olivenko.

“An invention of astronomers who look into their telescopes and hallucinate,” said Bleht.

“Our world,” persisted Rigg, “is a garden. And the Walls divide it into separate plots, where they grow their separate crops, not allowing them to mix their pollen or germinate their seeds outside the plot where they were planted.”

“Your supposed father taught you that?” asked Bleht.

“Not in so many words, but yes, I think he prepared me to learn that. And I think that’s what Father Knosso learned from the timeline and from you. The idea of different strains of life growing with uncrossable barriers between them—I think he guessed at the purpose of the Wall.”

“Much good it did him,” said Olivenko bitterly.

“How could he know that the creatures on the other side would kill him?” asked Rigg.

“This is all very amusing,” said Bleht. “Now I have real work to do. Next time you interrupt me, have something substantive to say.” There was no stopping her now. But as he watched her walk away, Rigg was pretty sure she was as intrigued by these ideas as he was. Why else did she stay to hear him out? Indeed, he had not really clarified his ideas or understood some of their ramifications until he had been in dialogue with her.

“Father Knosso was a seed, then,” said Olivenko, who had not let go of the conversation, though to him it was very personal, not theoretical at all. “A seed that wanted to plant itself in the next plot.”

“And the plants in the new plot rejected him,” said Rigg.

Suddenly Olivenko started breathing hard. For a moment Rigg thought, He’s awfully young to be having a heart attack. Then he realized that what he was seeing was sobs. Olivenko was crying, only he was doing his best to suppress the emotion, so the sobs were only visible and audible as gasps.

Rigg looked away until his guard’s breathing calmed again.

“I’m sorry,” said Olivenko.

“I understand,” said Rigg.

“All these years, I wondered if he was insane. That would put everything I learned from him into doubt. It’s why I gave up scholarship and turned to the opposite life. Because I had been caught up in the babblings of a madman.”

“He might have been insane,” said Rigg. “I’m his son—I might be just as mad.”

“You’re not,” said Olivenko. “He wasn’t. He wasn’t even wrong. He simply had the bad luck to find his way across the Wall at a place where they were waiting for him. How could he have known what they would do?”

“And so the mystery is solved,” said Rigg. “As far as we can solve it from the information that we have.”

They sat in their chairs in silence.

“What will you do now?” asked Olivenko.

“The only thing that makes any sense,” said Rigg. “There’s a power struggle going on in this city, with an empire as the prize to the cleverest, strongest, or most brutal player. A lot of those players want me dead. I need to find a way to escape from this city and hide where they can’t find me.”

“I’m probably not the person that you should have told.”

“You’re almost the only person I could tell, because you’re the only one who won’t think that I’m insane when I say it. Anywhere I try to hide within this wallfold, I’ll eventually be found. My only protection would be to join in the game—to try to assemble a military force and defeat all the others. To become a ruling emperor myself.”

“From what I’ve seen of you, I think you might just be able to do it.”

“I know a bit of history,” said Rigg. “Stupider men than I am have achieved it.” It sounded only a little ridiculous to Rigg, at his age to call himself a man. “But the only way for me to win is to walk to the Tent of Light over the bodies of hundreds, maybe thousands, of the very people I would be sworn to protect. To fight to save a kingdom from some threat, that would justify those deaths. But to fight only to save my own sorry life and become King-in-the-Tent—that’s not worth a single life.”

“Then what will you do?”

“I’ll leave the wallfold,” said Rigg.

Olivenko shook his head. “That doesn’t work as well as you might think.”

“I won’t escape by sea,” said Rigg. “Those creatures live in the water. Maybe I’d be safe on land. Or maybe, if I cross through the Wall far enough to the south of here, I’ll end up in a different wallfold from the one where Father Knosso died.”

“You search for the source of Father Knosso’s ideas about how to get through the Wall. You find out that he didn’t learn anything from the Great Library. So why do you think you know how to cross through the Wall?”

“The same way Father Knosso did,” said Rigg. “Make a guess, and see if it works.”

“What’s your guess?”

“I’m going to tell my guard?” said Rigg—but he smiled as he said it.

“It was worth a try,” said Olivenko.

“When they come to kill me—and they’ve already tried it twice, once on the journey here and on my first night in Flacommo’s house—is it your job to protect me or to help them do it?”

“Protect you,” said Olivenko. “I would never have taken an assignment to harm Father Knosso’s son, no matter how royal or irritating he might be.”

“I’ll tell you this much,” said Rigg. “When it comes time for me to escape from Flacommo’s house, I will do it, and there’s probably nothing you can do to stop me. But I like you. I don’t want you to be blamed for letting me get away. I’ll do it when someone else is in charge of watching me.”

“That’s very kind of you,” said Olivenko. “That will allow me to continue my brilliant military career without a blot on my record.”

“You have a better idea?”

“Take me with you,” said Olivenko.

“I told you,” said Rigg. “I’m not going to build an army. I’m going to cross through the Wall.”