“And you know,” he said softly, “that’s why it wants the crisis engine. It kept demanding it. Made me think. That’s what this is for.” He patted the circuit-valve. “If I connected the Council direct, it might be able to get feedback from the crisis engine, get control of it. It doesn’t know I’m using this, that’s why it was so keen on being connected. It doesn’t know how to build its own engine: you can bet Jabber’s arse that’s why it’s so interested in us.

“Dee, Yag, d’you know what this engine can do? I mean, this is a prototype…but if it works like it should, if you got inside this, saw the blueprint, built it more solidly, ironed out the problems…d’you know what this can do?

“Anything.” He was silent for a while, his hands working, connecting his wires. “There’s crisis everywhere, and if the engine can detect the field, tap it, channel it…it can do anything. I’m hamstrung because of all the maths. You’ve got to express in mathematical terms what you want the engine to do. That’s what the programme cards are for. But the Council’s whole damn brain expresses things mathematically. If that bastard links up to the crisis engine, its followers won’t be crazy any more.

“Because you know they call it the God-machine…? Well…they’ll be right.”

All three of them were quiet. Andrej rolled his eyes from side to side, not comprehending a single word.

Isaac worked silently. He tried to imagine a city in the thrall of the Construct Council. He thought of it linked up to the little crisis engine, building more and more of the engines on an ever-increasing scale, connecting them up to its own fabric, powering them with its own thaumaturgical and elyctrochymical and steampower. Monstrous valves hammering in the depths of the dump, making the fabric of reality bend and bleed with the ease of a Weaver’s spinnerets, all doing the bidding of that vast, cold intelligence, pure conscious calculation, as capricious as a baby.

He fingered the circuit-valve, shaking it gently, praying that its mechanisms were sound.

Isaac sighed and brought out the thick sheaf of programme cards the Council had printed. Each was labelled in the Council’s tottering typewritten script. Isaac looked up quizzically.

“It’s not yet ten, is it?” he said. Derkhan shook her head. “There’s still nothing in the air, is there? The moths aren’t out yet. Let’s be ready by the time they fly.”

He looked down and pulled the lever on the two chymical batteries. The reagents within mixed. The sound of effervescence was dimly audible, and there was a sudden chorus of chattering valves and barking outputs as current was released. The machinery on the roofscape snapped into life.

The crisis engine whirred.

“It’s just calculating,” said Isaac nervously, as Derkhan and Yagharek glanced at him. “It’s not yet processing. I’m giving it instructions.”

Isaac began to feed the programme cards carefully into the various analytical engines before him. Most went to the crisis engine itself, but some to the subsidiary calculating circuits connected by little loops of cable. Isaac checked each card, comparing it with his notes, scribbling quick calculations before feeding it into any of the inputs.

The engines clattered as their fine ratcheting teeth slid over the cards, snapping into carefully cut holes, instructions and orders and information downloading into their analogue brains. Isaac was slow, waiting until he felt the click that signalled successful processing before removing each card and slotting in the next.

He kept notes, scrawling impenetrable messages to himself on ragged ends of paper. He breathed quickly.

Rain began to fall, quite suddenly. It was sluggish, huge drops falling indolently and breaking open, as thick and warm as pus. The night was close, and the glutinous rainclouds made it more so. Isaac worked fast, his fingers feeling suddenly idiotic, too large.

There was a slow sense of dragging, a weightiness that pulled at the spirit and began to saturate the bones. A sense of the uncanny, of the fearful and hidden, that rolled up as if from within, a billowing ink-cloud from the depths of the mind.

“Isaac,” said Derkhan, her voice cracking, “you have to hurry. It’s starting.”

A swarm of nightmare feelings pattered down among them with the rain.

“They’re up and out,” said Derkhan with terror. “They’re hunting. They’re abroad. Hurry, you have to hurry…”

Isaac nodded without speaking and continued with what he was doing, shaking his head as if that might disperse the cloying fear that had settled on him. Where’s the fucking Weaver? he thought.

“Someone watches us from below,” said Yagharek suddenly, “some tramp who did not run. He does not move.”

Isaac glanced up again, then returned his attention to his work.

“Take my gun there,” he hissed. “If he comes up towards us, warn him off with a shot. Hopefully he’ll keep his distance.” Still his hands rushed to twist, to connect, to programme. He punched numbered keypads and wrestled roughcut cards into slots. “Nearly there,” he murmured, “nearly there.”

The sense of nocturnal pressure, of drifting in sour dreams, increased.

“Isaac…” hissed Derkhan. Andrej had fallen into a kind of terrified, exhausted half-sleep, and he began to moan and thrash, his eyes opening and shutting with bleary vagueness.

“Done!” spat Isaac, and stepped back.

There was a silent moment. Isaac’s triumph dissipated quickly.

“We need the Weaver!” he said. “It’s supposed to…it said it would be here! We can’t do anything without it…”

They could do nothing except wait.

The stench of twisted dream-imagery grew and grew, and brief screams sounded from random points across the city, as sleeping sufferers called out their fear or defiance. The rain fell thicker, until the concrete underfoot was slick. Isaac laid the greasy sack ineffectually across various sections of the crisis circuit, moving it in agitation, trying to protect his machine from the water.

Yagharek watched the glistening roofscape. When his head became too full of fearful dreams and he grew afraid of what he might see, he turned on his heel and watched through the mirrors on his helmet. He kept watch on the dim, immobile figure below.

Isaac and Derkhan dragged Andrej a little closer to the circuit (again with that ghastly gentleness, as if concerned for his well-being). Under Derkhan’s gun, Isaac retied the old man’s hands and legs, and fastened one of the communicator helmets tight to his head. He did not look at Andrej’s face.

The helmet had been adjusted. As well as its flared output on the top, it had three input jacks. One connected it to the second helmet. Another was connected by several skeins of wires to the calculating brains and generators of the crisis engine.

Isaac wiped the third connection briefly free of filthy rainwater, and plugged into it the thick wire extending from the black circuit-breaker, attached to which was the massive cable extending all the way to the Construct Council, south of the river. Current could flow from the Council’s analytical brain, through the one-way switch, into Andrej’s helmet.

“That’s it, that’s it,” said Isaac tensely. “Now we just need the fucking Weaver…”

It was another half an hour of rain and burgeoning nightmares before the dimensions of the roofspace rippled and shucked wildly, and the Weaver’s crooning monologue could be heard.