The Grandmaster's Gambit

26. Descent

[Day-30 (14:00)]

(The consolidation waterworks, under Sector 7, Alexandria)

The first rung was wet, and so was the second. Kai went down with the rope snug round his chest and the rag-wrapped lamp knocking against his spine at every step. Above him Cass's lamp swung from her belt and threw the shadow of the ladder down the shaft in long bars. Above her the rope ran up to Marcus.

He had eaten, as he'd been told. Cold barley and a heel of bread. The bolt on the door in Sector 9 had still been open when he left. He had looked at it from the landing and pulled the door to.

The hatch had been in the corner of a coal yard, under a Registry notice and a chain that someone had cut long ago and hung back in its links. At the bottom his boots found iron, and the sound of them went off into the dark and did not come back for a long time.

Cass's boots came down next, and then her lamp, and the room opened round it. It was a hall as long as a street. Pipes thick as wagons ran along both walls and up into the dark, held in iron rings. Between them stood valves the size of doors, each with a wheel on top as wide as a cart. The air was warm and wet. Her lamp was a lump of husk in a cage, and it burned the dull red of a coal. It made a small red room in the dark, and the dark outside it had a green tint, as if it had been soaked.

Kai looked down for something to do with his eyes. The floor was iron plates the size of doormats, and each one wore its own skin of green. No two matched. One was the black-green of an old bottle, and the next was the pale green of mould on bread.

*Forty greens. Nobody paints a floor like that. So they weren't painted. Maybe laid at different times? Different metal? Huh.*

Marcus came down last, and the rope went slack between them. "Heads," he said, and looked at Cass.

"Here."

"Aeron."

"Here."

"Marcus, here. Heads in."

A brass plate was bolted to the nearest pipe at head height, gone green round its screws. Cass raised her lamp to it.

> H. WRIGHT, ENGINEER.

> WALK WHERE THE RUST IS OLDEST.

> *Every vessel here can be emptied.*

The last line was cut smaller than the others, as if the engineer had thought of it later. Marcus laid two fingers on the plate as he passed, the way Oren touched a doorframe for luck.

"Wrights drain everything," he said. "Read the wheels."

"Who are the Wrights?"

"Engineers. They built all this before the Registry had its name on it."

*Wrights. So it's plural, meaning it's not one man. Builders, then. Like a cartwright, only for pipes. Read the wheels. All right.*

He read them as he walked, because he'd been told to. Each housing had a word stamped on a small plate. FEED. RELIEF. SERVICE. DRAIN. He couldn't tell what he was supposed to be reading for. Far above, through the stone, came the Sundial bell, one flat note and a long gap and another. It was so faint he might have been imagining it.

The hall narrowed ahead into two arches, and Marcus stopped between them.

The right arch opened on a walkway of brown iron, dry and dull, with a rail along one side and a black drop on the other. The left was wetter. Its floor shone green in Cass's light, and the plates were not scattered. They were set in a pattern, with strips of bare iron between them, and they ran away down the gallery until the lamp gave out.

Kai stepped up to the left arch and looked down it.

*Bright, dull, dull. Bright, dull, dull. All the way down till the light runs out. And the bright ones are dished in the middle. That's boots. Years of boots, they've worn the green right off. So that's where people put their feet, and the dull ones are where they didn't.*

*Oh, that's lovely. Somebody's drawn me a map and walked it for me.*

"Left," he said.

"Why?" said Marcus.

"Look at it. Bright, dull, dull, over and over. The bright ones are worn in the middle, see, that's boots. Somebody walked this gallery for years, and they only ever stepped on the bright ones."

"Or they walked the dull ones," Cass said, "and the dull ones ate them."

"Then there'd be no one left to wear the bright ones down."

"Could be a hundred people, once each."

"A hundred people and none of them went off. That's not a hundred accidents, that's a rule."

"A plate that's held a hundred boots has had a hundred chances to get tired," said Marcus. "I know what tired looks like. I've tied my life to it."

"That's a feeling."

"It's a rope." He didn't raise his voice. "Right gallery."

"It's a sequence, Marcus. Patterns are what I do. Give me ten minutes at the first three plates and I'll tell you the rule."

"I count the heads," said Marcus.

It was said the way he'd said *Crate* in the cellar. There was nothing to push against. The back of Kai's neck had gone hot, and he looked at the floor.

*I'd have had it in ten minutes.*

*Probably. Probably I would.*

"Right gallery," Marcus went on. "You read the floor for me as we go. You tell me which. I decide."

"Fine," said Kai.

Cass was looking down the left gallery, away from him. *Being tactful. Well that's great.*

The right gallery was mostly dry. Somewhere ahead water dripped, slow and even. The plates were brown, the rail was rusted through in places, and on the left a pipe as thick as a barrel was bolted to the wall every few strides. Its bolts wept thin brown tears down the iron.

Marcus went in front with his lamp held low, trying each plate with the toe of his boot before he gave it his weight. Kai followed a stride behind, and Cass came last with her light. The air was warm and wet, and he had pushed his sleeves up in the hall, as he had in the cellar, and never pulled them down.

"Left of the bolt," said Kai. "That one. Dark, flaky, it's been there a while. Skip the orange one. Orange is new."

Marcus tried the dark one and it held.

"Right side, two on. The dull one."

It held. The orange one beside it, when Marcus pressed it, rang hollow, and he stepped over it.

*Walk where the rust is oldest. It's a rule, so it's a rule I can read. Fresh rust's orange. Old goes brown, then black, then it builds up like crust. The older, the thicker.*

By the sixth plate he had stopped saying *I think*, and it was a small, real pleasure. They moved faster. Marcus waited for his word before he stepped.

Under the pipe, where a bolt wept, one plate was darker than all the rest. Its rust was as thick as a crust of bread, black-brown, heaped at the edges. Kai knelt and laid his left forearm along the plate's edge to lean in. A drop swelled on the bolt overhead, hung, and fell with a tick onto the plate. He watched it carefully.

*That's it. That's the oldest on the whole floor, look at it. Thick as a thumb. That's the Wrights' own plate, laid on day one and never touched.*

"This one," he said. "Look at the rust. It's the oldest on the gallery. That's what the plate said."

"You're sure," said Marcus.

"Yes."

Marcus put his boot on it.

The plate dipped by a finger's width. Under its edge, beside Kai's arm, something gave a small tick that he felt in his teeth, and his arm was already coming back.

Then the iron split with a sound like cloth tearing, and the world went white.

It came out sideways along the plate, a roaring wall of wet heat, and for a half breath it was only noise. Then a bowl of white fire stood over them. Cass's hand was up behind him. She had said a word. The fire was as wide as a cart and as high as Marcus's head. Every rush of steam that struck it ran off down its sides and fell away into the dark. It made no sound at all. The heat of it pressed on Kai's face from a hand's width off.

His left forearm lay outside its edge.

At first there was no pain. There was a flat hot slap with a weight in it, laid along the arm from wrist to elbow, and it did not come off.

Cass held the white up with her whole arm. *Marcus. Is he in it? He's standing. He's standing. And Aeron's arm is out past the edge and I can't pull it in without dropping the back. Can't. Too late. Marcus is standing.*

The steam thinned. The white came down and went out. Cass stood with her hand still raised, and the lamp she'd dropped lay on its side on the iron, burning red.

"Heads!" Marcus said. His voice was too loud. "Heads! Cass!"

"Here."

"Aeron!"

"Here."

"Marcus." He didn't finish it. He had taken the rope in both fists and hauled, and Kai slid back along the wet iron and was set against the rail. "Water. Over the arm. Now."

The flask was cold. Marcus poured it from wrist to elbow in a long even stream. Under the water the skin was bright red, and in the middle it had already gone white and tight, and a blister was lifting. The pain arrived then. It had edges, and the edges ran the whole length of the arm.

"It's fine," said Kai.

"It isn't." Marcus kept pouring. "It will be."

Cass had sat down on her heels. She held one hand in front of her face, and on the tip of her finger a flame the size of a bean stood up and burned. She watched it. The hand was shaking, and she waited until it was not. *The pipe didn't do that to her hand. I did, with a plate and a sentence, and it's still shaking.*

Cass tore a strip from the hem of her shirt, wet it from the flask, and laid it over the arm. She knotted it loose.

His left hand had started its shaking. He held it with the right.

"You called it," Marcus said.

"I did."

Marcus corked the flask. He said nothing about the rope or the left gallery. "Next time say *I think*," he said. "I can use *I think*. I can't do anything with *that's the one*. You tell me what you see, and I'll work out what it means."

"Right."

On the wet iron where the plate had been, a pale square lay for the length of a breath, the size of a slate. Then it went out.

*Oh, now. Now you show up. A breath late, as usual. And look where. Right under the plate. The one thing I was sure about, and it isn't even the pipe.*

He sat with the arm held out from his body and the wet strip stuck to it.

*I did it like a puzzle. Oldest rust, tick, next. But nobody laid this floor so I could solve it. They laid it for the day a pipe lets go. The one that looks wrong, that's the one they were thinking about.*

*A bad move in a game costs a tempo. You lose the next turn. This one cost Cass her hands and me my arm. And Marcus was right. I don't have to like it.*

He got up. It took two tries. Marcus did not help, and he did not step on the dead plate either. He tried the next with the toe of his boot and called back, "Cass. Aeron. Heads."

"Here."

"Here."

They went on along the gallery, Marcus in front and Kai a stride behind with his arm held clear. The wet strip began to dry. The unlit lamp knocked against his spine at every step, and behind them the broken plate went on weeping steam into the dark.