“And I can't get it to go backward,” he said.

“Don't worry,” said Simony. “It won't have to go backward. What about armor?”

Urn waved a distracted hand around his workshop.

“This is a village forge!” he said. “This thing is twenty feet long! Zacharos can't make plates bigger than a few feet across. I've tried nailing them on a framework, but it just collapses under the weight.”

Simony looked at the skeleton of the steam car and the pile of plates stacked beside it.

“Ever been in a battle, Urn?” he said.

“No. I've got flat feet. And I'm not very strong.”

“Do you know what a tortoise is?”

Urn scratched his head. “Okay. The answer isn't a little reptile in a shell, is it? Because you know I know that.”

“I mean a shield tortoise. When you're attacking a fortress or a wall, and the enemy is dropping everything he's got on you, every man holds his shield overhead so that it . . . kind of . . . slots into all the shields around it. Can take a lot of weight.”

“Overlapping,” murmured Urn.

“Like scales,” said Simony.

Urn looked reflectively at the cart.

“A tortoise,” he said.

“And the battering-ram?” said Simony.

“Oh, that's no problem,” said Urn, not paying much attention. “Tree-trunk bolted to the frame. Big iron rammer. They're only bronze doors, you say?”

“Yes. But very big.”

“Then they're probably hollow. Or cast bronze plates on wood. That's what I'd do.”

“Not solid bronze? Everyone says they're solid bronze.”

“That's what I'd say, too.”

“Excuse me, sirs.”

A burly man stepped forward. He wore the uniform of the palace guards.

“This is Sergeant Fergmen,” said Simony. “Yes, sergeant?”

“The doors is reinforced with Klatchian steel. Because of all the fighting in the time of the False Prophet Zog. And they opens outwards only. Like lock gates on a canal, you understand? If you push on 'em, they only locks more firmly together.”

“How are they opened, then?” said Urn.

“The Cenobiarch raises his hand and the breath of God blows them open,” said the sergeant.

“In a logical sense, I meant.”

“Oh. Well, one of the deacons goes behind a curtain and pulls a lever. But . . . when I was on guard down in the crypts, sometimes, there was a room . . . there was gratings and things . . . well, you could hear water gushing . . .”

“Hydraulics,” said Urn. “Thought it would be hydraulics.”

“Can you get in?” said Simony.

“To the room? Why not? No one bothers with it.”

“Could he make the doors open?” said Simony.

“Hmm?” said Urn.

Urn was rubbing his chin reflectively with a hammer. He seemed to be lost in a world of his own.

“I said, could Fergmen make these hydra haulics work?”

“Hmm? Oh. Shouldn't think so,” said Urn, vaguely.

“Could you?”

“What?”

“Could you make them work?”

“Oh. Probably. It's just pipes and pressures, after all. Um.”

Urn was still staring thoughtfully at the steam cart. Simony nodded meaningfully at the sergeant, indicating that he should go away, and then tried the mental interplanetary journey necessary to get to whatever world Urn was in.

He tried looking at the cart, too.

“How soon can you have it all finished?”

“Hmm?”

"I said-

“Late tomorrow night. If we work through tonight.”

“But we'll need it for the next dawn! We won't have time to see if it works!”

“It'll work first time,” said Urn.

“Really?”

“I built it. I know about it. You know about swords and spears and things. I know about things that go round and round. It will work first time.”

"Good. Well, there are other things I've got to do-

“Right.”

Urn was left alone in the barn. He looked reflectively at his hammer, and then at the iron cart.

They didn't know how to cast bronze properly here. Their iron was pathetic, just pathetic. Their copper? It was terrible. They seemed to be able to make steel that shattered at a blow. Over the years the Quisition had weeded out all the good smiths.

He'd done the best he could, but . . .

“Just don't ask me about the second or third time,” he said quietly to himself.

Vorbis sat in the stone chair in his garden, papers strewn around him.

“Well?”

The kneeling figure did not look up. Two guards stood over it, with drawn swords.

“The Turtle people . . . the people are plotting something,” it said, the voice shrill with terror.

“Of course they are. Of course they are,” said Vorbis. “And what is this plot?”

“There is some kind of . . . when you are confirmed as Cenobiarch . . . some kind of device, some machine that goes by itself . . . it will smash down the doors of the Temple . . .”

The voice faded away.

“And where is this device now?” said Vorbis.

“I don't know. They've bought iron from me. That's all I know.”

“An iron device.”

“Yes.” The man took a deep breath-half-breath, half-gulp. “People say . . . the guards said . . . you have my father in prison and you might . . . I plead . . .”

Vorbis looked down at the man.

“But you fear,” he said, “that I might have you thrown into the cells as well. You think I am that sort of person. You fear that I may think, this man has associated with heretics and blasphemers in familiar circumstances . . .”

The man continued to stare fixedly at the ground. Vorbis's fingers curled gently around his chin and raised his head until they were eye to eye.

“What you have done is a good thing,” he said. He looked at one of the guards. “Is this man's father still alive?”

“Yes, lord.”

“Still capable of walking?”

The inquisitor shrugged. “Ye-es, lord.”

“Then release him this instant, put him in the charge of his dutiful son here, and send them both back home.”

The armies of hope and fear fought in the informant's eyes.

“Thank you, lord,” he said.

“Go in peace.”

Vorbis watched one of the guards escort the man from the garden. Then he waved a hand vaguely at one of the head inquisitors.

“Do we know where he lives?”

“Yes, lord.”

“Good.”

The inquisitor hesitated.

“And this . . . device, lord?”

“Om has spoken to me. A machine that goes by itself? Such a thing is against all reason. Where are its muscles? Where is its mind?”

“Yes, lord.”

The inquisitor, whose name was Deacon Cusp, had got where he was today, which was a place he wasn't sure right now that he wanted to be, because he liked hurting people. It was a simple desire, and one that was satisfied in abundance within the Quisition. And he was one of those who were terrified in a very particular way by Vorbis. Hurting people because you enjoyed it . . . that was understandable. Vorbis just hurt people because he'd decided that they should be hurt, without passion, even with a kind of hard love.

In Cusp's experience, people didn't make things up, ultimately, not in front of an exquisitor. Or course there were no such things as devices that moved by themselves, but he made a mental note to increase the guard-

“However,” said Vorbis, “there will be a disturbance during the ceremony tomorrow.”

“Lord?”

“I have . . . special knowledge,” said Vorbis.

“Of course, lord.”

“You know the breaking strain of sinews and muscles, Deacon Cusp.”

Cusp had formed an opinion that Vorbis was somewhere on the other side of madness. Ordinary madness he could deal with. In his experience there were quite a lot of mad people in the world, and many of them became even more insane in the tunnels of the Quisition. But Vorbis had passed right through that red barrier and had built some kind of logical structure on the other side. Rational thoughts made out of insane components . . .

“Yes, lord,” he said.

“I know the breaking strain of people.”

It was night, and cold for the time of year.

Lu-Tze crept through the gloom of the barn, sweeping industriously. Sometimes he took a rag from the recesses of his robe and polished things.

He polished the outside of the Moving Turtle, which loomed low and menacing in the shadows.

And he swept his way toward the forge, where he watched for a while.

It takes extreme concentration to pour good steel. No wonder gods have always clustered around isolated smithies. There are so many things that can go wrong. A slight mis-mix of ingredients, a moment's lapse--

Urn, who was almost asleep on his feet, grunted as he was nudged awake and something was put in his hands.

It was a cup of tea. He looked into the little round face of Lu?Tze.

“Oh,” he said. “Thank you. Thank you very much.”

Nod, smile.

“Nearly done,” said Urn, more or less to himself. “Just got to let it cool now. Got to let it cool really slowly. Otherwise it crystallises, you see.”

Nod, smile, nod.

It was good tea.

“S'not 'n important cast anyway,” said Urn, swaying. "Jus' the control levers-

Lu-Tze caught him carefully and steered him to a seat on a heap of charcoal. Then he went and watched the forge for a while. The bar of steel was glowing in the mold.

He poured a bucket of cold water over it, watched the great cloud of steam spread and disperse, and then put his broom over his shoulder and ran away hurriedly.

People to whom Lu-Tze was a vaguely glimpsed figure behind a very slow broom would have been surprised at his turn of speed, especially in a man six thousand years old who ate nothing but brown rice and drank only green tea with a knob of rancid butter in it.

A little way away from the Citadel's main gates he stopped running and started sweeping. He swept up to the gates, swept around the gates themselves, nodded and smiled at a soldier who glared at him and then realized that it was only the daft old sweeper, polished one of the handles of the gates, and swept his way by passages and cloisters to Brutha's vegetable garden.

He could see a figure crouched among the melons.

Lu-Tze found a rug and padded back out into the garden, where Brutha was sitting hunched up with his hoe over his knees.

Lu-Tze had seen many agonized faces in his time, which was a longer time than most whole civilizations managed to see. Brutha's was the worst. He tugged the rug over the bishop's shoulders.

“I can't hear him,” said Brutha hoarsely. “It may mean that he's too far away. I keep on thinking that. He might be out there somewhere. Miles away!”

Lu-Tze smiled and nodded.

“It'll happen all over again. He never told anyone to do anything. Or not to do anything. He didn't care!”

Lu-Tze nodded and smiled again. His teeth were yellow. They were in fact his two-hundredth set.

“He should have cared.”

Lu-Tze disappeared into his corner again and returned with a shallow bowl full of some kind of tea. He nodded and smiled and proffered it until Brutha took it and had a sip. It tasted like hot water with a lavender bag in it.