“Time, well, nobody can stop it, yeasay? And space, that’s what keeps everything from mashing together—so what’ve they got in common?”

Toby was trying to provoke her, but Quath took it all very solemnly. Gravely she explained.

Listening, Toby caught an occasional glimmering. Humans had an awareness of things becoming, bursting forth into concrete solidity, and then fading into a limbo of memory. Quath said that space-time, the esty, contained real time, and the transience of human experiences was only an illusion peculiar to living creatures.

And what did their opinion matter, Toby thought wryly, since they were around for such a short glimmering? His Isaac Aspect tendered up an ancient rhyme,

Time goes, you say? ah no!

Alas, time stays, we go.

—and cackled with weird glee.

They passed by huge blank timestone walls, porous with blurred light. Giant towers worked and popped with energy nearby, growing like triangular trees. Some seemed able to shiver the sky and wrench the stars apart with their restless energy. Quath and Toby hurried by. They ventured with scarcely a pause into abrupt turns, mazy avenues of timestone. Toby had kept himself in pretty fair condition on Argo, he thought, but he had a trial in just keeping Quath within sight. His lungs burned. Servos ran hot.

He stopped abruptly. “Quath, I was wrong. Dead wrong.”

<How?>

“We’ve run out on the Family. That bird—what if mechs’re all over this place now?”

<You believe the mechanicals will seek all the humans here?>

“Bishops, anyway. Come on.”

<Where?>

“I’m heading back.”

He felt good about himself for the next few hours, while they backtracked. Quath kept quiet. After a while Toby saw why.

“Uh . . . which way from here?”

<I do not know.>

“We came this way, yeasay?”

<Indeed.>

“The Lane connection, it was somewhere around here.” Hills, trees, sky—all different.

<The esty is strongly stochastic at the Lane connections, for those are the instability loci.>

Toby sagged down, eyes blank. “So we can’t find our way back?”

<I fear not.>

So they reversed again. Fruitlessly returning over the same ground was demoralizing. And the terrain was subtly different, which deepened Toby’s gloom. He had run away from his father, straight into a trap. A place that forgave no errors.

Quath kept looking around, studying, distracted. When he asked her why, she said, <I am letting stochasticity—that is, chance—choose to favor us.>

“I—I don’t get it. What’re we looking for?”

<An obliging accident.>

“Sounds like a contradiction in terms.” He panted hard, slippery air clogging his throat.

<You told me once of a simple puzzle you had solved. Here:>

Into his sensorium framed a pattern of paired numbers.

1 100

2 99

3 43

61 97

5 96

* *

* *

50 51

“You messed it up. Each pair was supposed to add up to a hundred and one. There were fifty of them, so that multiplied out to, uh, to five thousand and fifty.”

<True. But in this sum I merely rearranged the numbers in a random way—but I kept them all, so that the total remains four thousand nine hundred ninety-nine. The esty is so devised. What Andro called the Lanes are subsets of the entire spacetime here, tunnels opening and closing at random. But the sum of it all—the four thousand nine hundred ninety-nine of it—remains the same. Nothing is gained or lost.>

“Uh, okay. What’s the point?”

<The esty conserves itself. But the continual shifting of the Lanes makes a map of the esty impossible. Relying on the stochastic nature of the interplaying Lanes is the only way to protect them.>

“The mechs can’t find any particular Lane, because it’s never in the same place twice?”

<Or the same when.>

“Hiding in time, not space?”

<In both—in esty. The Lanes evolve by interacting. The falling of a single timestone can multiply its effect, building disorder. Similarly, in a planet’s weather, a mere passing wind can stir forth a storm. Scrambling the esty Lanes rearranges them in time and space. No mathematical algorithm can unbind them or trace their evolution. Security rests on the firm rock of chaos.>

Toby slowed, the idea sinking in. People had hid out here. Long ago, in the Hunker Down Era. Back then Bishops and all the Families had dug into the planets for protection, figuring the mechs worked best in space.

But some fraction of humanity had fled into the esty’s chaos. Mechs could not map this spaghetti space, so they could never be sure of finding all human colonies. He could see what Quath meant with the arithmetic, sort of. But the weirdness of it remained—that disorder was safer than planets, tougher to untie than snarled barbed wire.

Numbers could hold simple, supple majesty. Maybe the strangest part of all this was that reality reflected the dance of numbers. Laws compelled the esty to knot and flex, laws ruled by the skittering logic of chaos. Compared to that mystery, the mechs seemed almost ordinary.

“So where do we go?”

<Forward. The farther we go, the more tangled our path becomes.>

“How’ll we ever get back to the Family?”

<I do not know. I suspect that they, too, will enter this labyrinth.>

“Following us?”

<Do not forget Abraham.>

“Yeasay. Let’s find him first.” He nodded to himself. Having a sense of purpose made him feel better. And this was a better place to be than stuck inside Argo, by far.

<You are following your species-specific behavior.>

Toby had the uneasy feeling that Quath knew what he was thinking. “How’s that?”

<Your primate societies often were ripe with ritual journeys. Young men went off on quests into unknown lands. They had adventures, learned much, and returned transformed.>

“You been studying us again?”

<I do always.>

Toby had been feeling guilty about enjoying this, especially now that they couldn’t get back to the Family. “We’re not so damned predictable!”

<I note patterns. You may have needed to escape the father, in order to define yourself.>

“Hey, you’re pretty heavy with the crap here.”

<I am trying to understand a very strange species.>

“Sometimes understanding’s the booby prize, buggo.” Toby laughed and put all such theorizing out of his mind. It was a luxury, the kind of thing people in cities did. He settled into the rhythm of the run.

He watched the landscape with wary respect, aware now that it took time to shape time. Esty storms had carved out intricate canyons of compacted instants. Compressions and twistings made unscalable walls, stomach-turning drop-offs, boxlike traps of curved, silent timestuff.

Moving through the gasping-hard slopes and sudden gaps was exhausting. Quath had ample energy, but the pace began to tell on Toby. He kept looking back to check for signs of pursuit. Unbidden, his father’s words in their last encounter pealed through his mind.

Shibo was there to comfort him, to immerse sharp memory in her soft presence. She sang and delighted him, distractions galore.

Still, the feeling of pursuit would not leave him. His calves began to ache, his breath rasped. He forced himself to keep up with Quath’s great bulk, which seemed to flow easily over the jumbles of gravel and swelling rock.

Finally, when Toby was sweating hard, they took a break at the base of a steep cliff. Quath lowered herself to an easeful position atop her legs and seemed to fall instantly asleep, the first sign he had ever had that she slept at all. Or maybe, with her multiple minds, she was just resting, and letting some fraction of herself stay on watch.