"I suppose I knew that," said Afsan, "but that’s not my point. Saleed judged each of us, each of his young apprentices. And all of them, save me, were sent back to the Packs from which they’d come."

"And that disturbed you?"

"It was frightening — not knowing if I’d be sent back next; whether I was the one he’d been looking for, or whether he’d get rid of me, too."

"But you never met any of the other apprentices?"

"No." A pause. "Saleed used to talk about them from time to time, though. Always in disparaging terms. The fellow before, his name was Pog-Teevio. I had to wear his leftover sashes. But he’d been older than I was, so the sashes had been altered to fit me. You could tell where material had been removed — since the sashes were tapered, the pieces didn’t line up properly and had to be trimmed." A pause. "God, how I hated those sashes."

"How many apprentices did Saleed have before you?"

"Well, let’s see. There was Pog-Teevio. Before him was Adkab. Before him was, um, Rikgot. Before her, Haltang. You know, as an aside, I wish I hadn’t known their names. It made it a lot harder, contemplating what had happened to them, knowing their names."

"Was Haltang the first?"

"No, there were two before him. Females both: Lizhok and — oh, what was it now? — Tasnik."

"That’s a total of six before you."

"Yes."

"And you were number seven."

Irritated. "That follows, doesn’t it? Yes. The seventh."

"It bothered you that your future at the palace was unsure."

"Wouldn’t it bother you? When I’d been summoned to Capital City, I’d had no idea that Saleed had had all those previous apprentices, all of whom had proved unsuitable."

"But as your time at the palace grew longer and longer, surely the fear that you’d be sent back must have diminished?"

"Diminished?" Afsan clicked teeth derisively. "That shows how little you know, Mokleb. It grew worse. I kept waiting for the eighth apprentice to arrive."

"How did you know there would be an eighth?"

"Well, of course, it turned out there wasn’t, but I felt sure, sure in my bones, that there would be one more."

"Six before you, you as the seventh, and one more, for a total of eight," said Mokleb.

"And they call me a mathematical genius."

"Eight, of whom seven would be sent back."

"Yes."

"Of whom seven would be dispatched."

"As you say."

"And Saleed sat in constant judgment of you."

"Yes. Just like you do."

"I don’t judge you at all, Afsan. It’s not my place. But you felt judged by Saleed. Six had already been sent back. If you failed, you’d be sent back, too."

"It wasn’t so much a question of ’if.’ I eventually became sure I’d be sent back; I knew there had to be one further apprentice."

Mokleb was quiet for a time, waiting to see if Afsan would offer anything further. At last she said, "Do you see the pattern you’re describing?"

A sneer. "What pattern?"

"Eight youngsters, judged by a vastly older authority figure. Seven of them dispatched — your word, that — and only the eighth surviving."

"Yes. So?"

"It sounds precisely like the culling of the bloodpriest. Seven out of eight hatchlings in every clutch are devoured."

Afsan clicked his teeth derisively. "You’re way off base, Mokleb. By God’s own tail, I knew this whole process was a waste of time. Roots, you see patterns in everything! For your information, Doctor, I knew nothing at all about bloodpriests until after I’d left Saleed to go on my journey around the world. It wasn’t until I was on my return trip to Capital City, when I stopped off in Carno for a visit, that I first learned about the bloodpriests. For God’s sake, Mokleb, the nonsense you spout!"

Bos-Karshirl, a young female engineer Novato had requested some time ago from Capital City, arrived by boat on a foggy even-day. The two of them stood on the pebbly beach and looked up at the massive blue pyramid and the tower rising out of its apex. The tower disappeared after a short distance into the gray gloom.

"Incredible," said Karshirl. She turned and bowed to Novato. "I agree: this is a fascinating thing for an engineer to study. Thank you for requesting me — although I’ll admit I’m surprised you asked for me. I’m young, after all; there are much older and more experienced engineers who would enjoy a chance to examine this."

"You’re not that young, Karshirl," said Novato. "You’re eighteen or so; I was just eleven, an apprentice glassworker, when I invented the far-seer."

"Still…" said Karshirl, then, evidently deciding not to press her good fortune, "Thank you very much. I do appreciate the opportunity." The younger female leaned back on her tail and looked up at the tower, lost in the fog. "How tall is the tower?" she asked

"I have no idea," said Novato.

Karshirl clicked her teeth. "Good Novato, have you forgotten your trigonometry? All you have to do is move a known distance from the tower’s base — a hundred paces, say — then note the angle between the ground and the top of the tower. Any good set of math tables will give you the height."

"Of course," said Novato. "But that’s predicated on the assumption that one can see the top of the tower. But we can’t, even on the clearest of days. The tower simply goes up and up, straight to the zenith. I’ve seen it pierce right through clouds, with the cloud looking like a gobbet of meat skewered on a fingerclaw. The tower is sufficiently narrow that it fades from view before its summit is reached. The best time to view it is on clear mornings just before dawn, when the tower itself is already illuminated by the sun, but the sky is still dark. Still, I can’t make out its apex. I’ve looked at its upper reaches with a far-seer, and, again, it fades from view rather than coming to a discrete end."

"That’s incredible," said Karshirl.

"Indeed."

"But wait — there’s another way to measure it. You’ve said there is a vehicle of some kind moving up its interior?"

"Several, as it turns out. We call them lifeboats."

"Well, all you have to do is mark one of the lifeboats, so you can be sure to recognize the same one later. Measure the distance between two of the tower’s rungs — you can do that, at least, with trig, even if you can’t actually reach the rungs. Choose a couple of rungs that are a good distance apart and also are a good ways up the shaft so that the lifeboat will be up to speed by the time it passes them. Then simply see how long it takes for a lifeboat to traverse that distance. That will give you its traveling speed. After that, all you have to do is wait for the lifeboat to make a round trip up and down the shaft. Assuming the lifeboats do indeed go all the way to the top, and assuming they travel at a constant speed, you’ll be able to calculate the tower’s height by dividing half the total elapsed time by the lifeboat’s known speed."

If Karshirl had been looking at Novato, instead of tipping her muzzle up at the tower, she’d have stopped before getting to the end of her explanation, since Novato’s face made it clear that she’d already thought of all this. "We tried that, of course," said Novato. "The lifeboats accelerate quickly at first, but almost immediately seem to reach their maximum velocity. It seems the lifeboats are moving at something like one hundred and thirty kilopaces per day-tenth."

"Good God!" said Karshirl, her eyelids strobing up and down. "That’s faster than even a runningbeast can manage."

"Twice as fast, to be precise," said Novato. "And it takes the lifeboats — wait for this — twenty days to make the round trip. Now, granted, there’s a lot of room for error — these are just back-of-a-sash calculations — but if you do the math, that would imply that the tower is on the order of thirteen thousand kilopaces tall."

"But, good Novato, our entire world has a diameter of only twelve thousand kilopaces," said Karshirl. "You can’t be seriously suggesting that the tower is taller than our world is wide. Something must be going on that we can’t see. The lifeboats must stop at the top for days on end, or else slow down once they get out of sight."