“He's only a few hundred yards over there,” she said, pointing to a frozen drift.

“And I know when he is,” said Lobsang. “Only sixty thousand years away. So…”

Lu-Tze, when they found him, was looking calmly up at an enormous mammoth. Under its huge hairy brow its eyes were squinting with the effort both of seeing him and of getting all three of its brain cells lined up so that it could decide whether to trample on him or gouge him out of the frost-bound landscape. One brain cell was saying “gouge”, one was going for “trample” but the third had wandered off and was thinking about as much sex as possible.

At the far end of its trunk, Lu-Tze was saying, “So, you've never heard of Rule One, then?”

Lobsang stepped out of the air beside him. “We must go, Sweeper!”

The appearance of Lobsang did not seem to surprise Lu-Tze at all, although he did seem annoyed at the interruption.

“No rush, wonder boy,” he said. “I've got this perfectly under control—”

“Where's the lady?” said Susan.

“Over by that snowdrift,” said Lu-Tze, indicating with his thumb while still trying to outstare a pair of eyes five feet apart. “When this turned up she screamed and twisted her ankle. Look, you can see I've made it nervous—”

Susan waded into the drift and hauled Unity upright. “Come on, we're leaving,” she said brusquely.

“I saw his head cut off!” Unity babbled. “And then suddenly we were here!”

“Yes, that kind of thing happens,” said Susan.

Unity stared at her, wild-eyed.

“Life is full of surprises,” said Susan, but the sight of the creature's distress made her hesitate. All right, the thing was one of them, one that was merely wearing—Well, at least had started out merely wearing a body as a kind of coat, but now… After all, you could say that about everyone, couldn't you?

Susan had even wondered if the human soul without the anchor of a body would end up, eventually, as something like an Auditor. Which, to be fair, meant that Unity, who was getting more firmly wrapped in flesh by the minute, was something like a human. And that was a pretty good definition of Lobsang and, if it came to it, Susan as well. Who knew where humanity began and where it finished?

“Come along,” she said. “We've got to stick together, right?”

Like shards of glass, spinning through the air, fragments of history drifted and collided and intersected in the dark.

There was a lighthouse, though. The valley of Oi Dong held on to the ever-repeating day. In the hall almost all of the giant cylinders stood silent, all time run out. Some had split. Some had melted. Some had exploded. Some had simply vanished. But one still turned.

Big Thanda, the oldest and largest, ground slowly on its basalt bearing, winding time out at one end and back on the other, ensuring as Wen had decreed that the perfect day would never end.

Rambut Handisides was all alone in the hall, sitting beside the turning stone in the light of a butter lamp and occasionally throwing a handful of grease onto the base.

A clink of stone made him peer into the darkness. It was heavy with the smoke of fried rock.

There the sound was again and, then, the scratch and flare of a match.

“Lu-Tze?” he said. “Is that you?”

“I hope so, Rambut, but who knows, these days?” Lu-Tze stepped into the light and sat down. “Keeping you busy, are they?”

Handisides sprang to his feet. “It's been terrible, Sweeper! Everyone's up in the Mandala Hall! It's worse than the Great Crash! There's bits of history everywhere and we've lost half the spinners! We'll never be able to put it all—”

“Now, now, you look like a man who's had a busy day,” said Lu-Tze kindly. “Not got a lot of sleep, eh? Tell you what, I'll take care of this. You go and get a bit of shut-eye, okay?”

“We thought you were lost out in the world, and—” the monk burbled.

“And now I'm back,” smiled Lu-Tze, patting him on the shoulder. “There's still that little alcove round the corner where you repair the smaller spinners? And there's still those unofficial bunks for when it's the night shift and you only need a couple of lads to keep their eye on things?”

Handisides nodded, and looked guilty. Lu-Tze wasn't supposed to know about the bunks.

“You get along, then,” said Lu-Tze. He watched the man's retreating back and added, quietly, “and if you wake up you might turn out to be the luckiest idiot that ever there was. Well, wonder boy? What next?”

“We put everything back,” said Lobsang, emerging from the shadows.

“You know how long that took us last time?”

“Yes,” said Lobsang, looking around the stricken hall and heading towards the podium, “I do. I don't think it will take me as long.”

“I wish you sounded more certain,” said Susan.

“I'm… pretty certain,” said Lobsang, running his fingers over the bobbins on the board.

Lu-Tze waved a cautionary hand at Susan. Lobsang's mind was already on the way to somewhere else, and now she wondered how large a space it was occupying. His eyes were closed.

“The… spinners that axe left… Can you move the jumpers?” he said.

“I can show the ladies how to,” said Lu-Tze.

“Are there not monks who know how to do this?” said Unity.

“It would take too long. I am an apprentice to a sweeper. They would run around asking questions,” said Lobsang. “You will not.”

“He's got a point right enough,” said Lu-Tze. “People will start saying ‘What is the meaning of this?’ and ‘Bikkit!’, and we'll never get anything done.”

Lobsang looked down at the bobbins and then across at Susan.

“Imagine… that there is a jigsaw, all in pieces. But… I am very good at spotting edges and shapes. Very good. And all the pieces are moving. But because they were once linked, they have by their very nature a memory of that link. Their shape is the memory. Once a few are in the right position, the rest will be easier. Oh, and imagine that all the bits are scattered across the whole of eventuality, and mixing randomly with pieces from other histories. Can you grasp all that?”

“Yes. I think so.”

“Good. Everything I have just said is nonsense. It bears no resemblance to the truth of the matter in any way at all. But it is a lie that you can… understand, I think. And then, afterwards—”

“You're going to go, aren't you,” said Susan. It was not a question.

“I will not have enough power to stay,” said Lobsang.

“You need power to stay human?” said Susan. She hadn't been aware of the rise of her heart, but now it was sinking.

“Yes. Even trying to think in a mere four dimensions is a terrible effort. I'm sorry. Even to hold in my mind the concept of something called ‘now’ is hard. You thought I was mostly human. I'm mostly not.” He sighed. “If only I could tell you what everything looks like to me… it's so beautiful.”

Lobsang stared into the air above the little wooden bobbins. Things twinkled. There were complex curves and spirals, brilliant against the blackness.

It was like looking at a clock in pieces, with every wheel and spring carefully laid out in the dark in front of him. Dismantled, controllable, every part of it understood… but a number of small but important things had gone ping into the corners of a very large room. If you were really good, then you could work out where they'd landed.

“You've only got about a third of the spinners,” came the voice of Lu-Tze. “The rest are smashed.”

Lobsang couldn't see him. There was only the glittering show before his eyes.

“That… is true, but once they were whole,” he said. He raised his hands and lowered them onto the bobbins.

Susan looked around at the sudden grinding noise and saw row after row of columns rising out of the dust and debris. They stood like lines of soldiers, rubble cascading from them.