“Some total idiot,” said Susan. She tried to think of other things, and added, “We didn't get all of them. There's still Auditors down there somewhere.”

“That will not matter,” said Unity calmly. “Look at the sun.”

“Well?”

“It is setting.”

“And…?”

“That means time is flowing through the world. The body exacts its toll Susan. Soon my—my former colleagues, bewildered and fleeing, will become tired. They will have to sleep.”

“I follow you, but—”

“I am insane. I know this. But the first time it happened to me I found such horror that I cannot express it. Can you imagine what it is like? For an intellect a billion years old, in a body which is an ape on the back of a rat that grew out of a lizard? Can you imagine what comes out of the dark places, uncontrolled?”

“What are you telling me?”

“They will die in their dreams.”

Susan thought about this. Millions and millions of years of thinking precise, logical thoughts—and then humanity's murky past drops all its terrors on you in one go. She could almost feel sorry for them. Almost.

“But you didn't,” she said.

“No. I think I must be… different. It is a terrible thing to be different, Susan. Did you have romantic hopes in connection with the boy?”

The question came out of nowhere and there was no defence. Unity's face showed nothing but a kind of nervous concern.

“No,” said Susan. Unfortunately, Unity did not seem to have mastered some of the subtleties of human conversation, such as when a tone of voice means “Stop this line of inquiry right now or may huge rats eat you by day and by night.”

“I confess to strange feelings regarding his… self that was the clockmaker. Sometimes, when he smiled, he was normal. I wanted to help him, because he seemed so closed in and sad.”

“You don't have to confess to things like that,” Susan snapped. “How do you even know the word romantic, anyway?” she added.

“I found some books of poetry.” Unity actually looked embarrassed.

“Really? I've never trusted it,” said Susan. Huge, giant, hungry rats.

“I found it most curious. How can words on a page have a power like that? There is no doubt that being human is incredibly difficult and cannot be mastered in one lifetime,” said Unity sadly.

Susan felt a stab of guilt. It wasn't Unity's fault, after all. People learn things as they grow up, things that never get written down. And Unity had never grown up.

“What are you going to do now?” she said.

“I do have a rather human ambition,” said Unity.

“Well, if I can help in any way…”

It was, she realized later, one of those phrases like “How are you?” People were supposed to understand that it wasn't a real question. But Unity hadn't learned that, either.

“Thank you. You can indeed help.”

“Uh, fine, if—”

“I wish to die.”

And, galloping out of the sunset, some riders were approaching.

Tick

Small fires burned in the rubble, brightening the night. Most of the houses had been completely destroyed, although, Soto considered, the word “shredded” was much more accurate.

He was sitting by the side of the street, watching carefully, with his begging bowl in front of him. There were of course far more interesting and complex ways for a History Monk to avoid being noticed, but he'd adopted the begging bowl method ever since Lu-Tze had shown him that people never see anyone who wants them to give him money.

He'd watched the rescuers drag the bodies out of the house. Initially they'd thought that one of them had been hideously mutilated in the explosion, until it had sat up and explained that it was an Igor and in very good shape for an Igor, at that. The other he'd recognized as Dr Hopkins of the Guild of Clockmakers, who was miraculously unharmed.

Soto did not believe in miracles, however. He was also suspicious about the fact that the ruined house was full of oranges, that Dr Hopkins was babbling about getting sunlight out of them, and that his sparkling little abacus was telling him that something enormous had happened.

He decided to make a report and see what the boys at Oi Dong said.

Soto picked up the bowl and set off through the network of alleys back to his base. He didn't bother much about concealment now; Lu-Tze's time in the city had been a process of accelerated education for many citizens of the lurking variety. The people of Ankh-Morpork knew all about Rule One.

At least, they had known until now. Three figures lurched out of the dark, and one of them swung a heavy cleaver which would have connected with Soto's head if he hadn't ducked.

He was used to this sort of thing, of course. There was always the occasional slow learner, but they presented no peril that a neat slice couldn't handle.

He straightened up, ready to ease his way out of there, and a thick lock of black hair fell onto his shoulder, slithered down his robe and flopped onto the ground. It made barely a sound, but the expression on his face as Soto looked down and then up at his attackers made them draw back.

He could see, through the blood-red rage, that they all wore stained grey clothes and looked even crazier than the usual alley people; they looked like accountants gone mad.

One of them reached out towards the begging bowl.

Everyone has a conditional clause in their life, some little unspoken addition to the rules like “except when I really need to” or “unless no one is looking” or, indeed, “unless the first one was nougat”. Soto had for centuries embraced a belief in the sanctity of all life and the ultimate uselessness of violence, but his personal conditional clause was “but not the hair. No one touches the hair, okay?”

Even so, everyone ought to have a chance.

The attackers recoiled as he threw the bowl against the wall, where the hidden blades buried themselves in the woodwork.

Then it began to tick.

Solo ran back down the alley, skidded round the corner and then shouted, “Duck!”

Unfortunately for the Auditors, alas, he was just a tiny, tiny fraction of a second too late—

Tick

Lu-Tze was in his Garden of Five Surprises when the air sparkled and fragmented and swirled into a shape in front of him.

He looked up from his ministrations to the yodelling stick insect, who'd been off its food.

Lobsang stood on the path. The boy was wearing a black robe dotted with stars, which blew and rattled its rags around him on this windless morning as if he was standing in the centre of a gale. Which, Lu-Tze supposed, he more or less was.

“Back again, wonder boy?” said the sweeper.

“In a way, I never leave,” said Lobsang. “Things have gone well with you?”

“Don't you know?”

“I could. But part of me has to do this the traditional way.”

“Well, the abbot is mighty suspicious and there's some amazing rumours flying around the place. I didn't say much. What do I know about anything? I'm just a sweeper.”

With that, Lu-Tze turned his attention to the sick insect. He'd counted to four under his breath before Lobsang said: “Please? I have to know. I believe that the fifth surprise is you. Am I right?”

Lu-Tze cocked his head. A low noise, which he'd heard for so long he no longer consciously heard it, had changed its tone.

“The spinners are all winding out,” he said. “They know you're here, lad.”

“I shall not be here long, Sweeper. Please?”

“You just want to know my little surprise?”

“Yes. I know nearly everything else,” said Lobsang.

“But you are Time. What I tell you in the future you'll know now, right?”

“But I'm partly human. I want to stay partly human. That means doings things the right way round. Please?”