The Weaver danced on in delight.

An enormous beacon was scorched into the aether. A huge and rapidly growing column of energy, a pretend consciousness, the map of a counterfeit mind that swelled and fattened in a fearful curve of growth, impossible and vastly there, the portent of a nonexistent god.

Across New Crobuzon, more than nine hundred of the city’s best communicators and thaumaturges paused and looked suddenly in the direction of The Crow, their faces twisted with confusion and nebulous alarm. The most sensitive held their heads and moaned with inexplicable pain.

Two hundred and seven began to jabber in nonsense combinations of numerological code and lush poetry. One hundred and fifty-five suffered massive nosebleeds, two of them ultimately un-staunchable and fatal.

Eleven, who worked for the government, scrabbled from their workshop at the top of the Spike and ran, with handkerchiefs and tissues ineffectually stopping the bloody slick from their noses and ears, towards Eliza Stem-Fulcher’s office.

“Perdido Street Station!” was all they could say. They gabbled it like idiots for some minutes, to the home secretary and the mayor who was with her, shaking them with frustration, their lips twitching for other sounds, blood spattering their bosses’ immaculate tailoring.

“Perdido Street Station!”

Way out above the wide empty streets of Chnum; swooping slowly past the curve of temple towers in Tar Wedge; skirting the river above Howl Barrow and soaring widespread over the pauper slum of Stoneshell, intricate bodies moved.

With sluggish strokes and drooling tongues, the slake-moths sought prey.

They were hungry, eager to gorge themselves and ready their bodies and breed again. They must hunt.

But in four sudden, identical and simultaneous movements-separated by miles, in different quadrants of the city-the four slake-moths snapped their heads up as they flew.

They beat their complex wings and slowed, until they were almost still in the air. Four slobbering tongues lolled and lapped at the air.

In the distance, over the skyline that glimmered with grots of filthy light, on the outskirts of the central mass of building, a column was rising from the earth. Even as they licked and taste-smelled it, it grew and grew, and their wings beat back frantically as the wafts of flavour came over them, and the incredible succulent stench of the thing boiled and eddied in the aether.

The other smells and tastes of the city dissipated into nothing. With an amazing speed, the extraordinary flavour-trail doubled its intensity, suffusing the slake-moths, making them mad.

One by one they emitted a chittering of astounded, delighted greed, a single-minded hunger.

From all the way across the city, from the four compass points, they converged in a frenzy of flapping, four starving exultant powerful bodies, descending to feed.

There was a tiny putter of lights on a little console. Isaac edged closer, keeping his body low, as if he could duck under the beacon of energy pouring from Andrej’s skull. The old man lolled and twitched on the ground.

Isaac was careful not to look at Andrej’s sprawling form. He peered at the console, making sense of the little play of diodes.

“I think it’s the Construct Council,” he said over the drab rainfall sound. “It’s sending instructions to get round the firewall, but I don’t think it’ll be able to. This is too simple for it,” he said, and patted the circuit-valve. “There’s nothing for it to get control of.” Isaac visualized a struggle in the femtoscopic byways of wiring.

He looked up.

The Weaver was ignoring him and them all, drumming its little fingers against the slick concrete in complicated rhythms. Its low voice was impenetrable.

Derkhan was staring in exhausted disgust at Andrej. Her head jerked gently back and forward as if she was rocked by waves. Her mouth moved. She spoke in silent tongues. Don’t die, thought Isaac fervently, staring at the ruined old man, seeing his face contort as bizarre feedback rocked him, you can’t die yet, you have to hold on.

Yagharek was standing. He pointed up, suddenly, into a far quadrant of the sky.

“They have changed course,” he said harshly. Isaac looked up and saw what Yagharek was indicating.

Far away, halfway to the edge of the city, three of the drifting dirigibles had turned purposefully. They were hardly visible to human eyes, darker blots against the night sky, picked out with navigation lights. But it was clear that their fitful, random motion had changed; that they were powering ponderously towards Perdido Street Station, converging.

“They’re on to us,” said Isaac. He did not feel fearful, only tense and weirdly sad. “They’re coming. Godspit and shit! We’ve got about ten, fifteen minutes before they get here. We just have to hope the moths are quicker.”

“No. No.” Yagharek was shaking his head with quick violence. His head was cocked. His arms moved quickly, motioning them all to silence. Isaac and Derkhan froze. The Weaver continued its insane monologue, but it was subdued and hushed. Isaac prayed that it would not become bored and disappear. The apparatus, the constructed mind, the crisis would all collapse.

The air around them all was welting, splitting like troubled skin, as the force of that unthinkable and burgeoning blast of power continued to grow.

Yagharek was listening intently through the rain.

“People are approaching,” he said urgently, “across the roof.” With practised movements, he plucked his whip from his belt. His long knife seemed to dance into his left hand and pose, glinting in the refracted sodium lights. He had become a warrior and a hunter again.

Isaac stood and drew his flintlock. He checked hurriedly that it was clean and he filled the pan with powder, trying to shield it from the rain. He felt for his little pouch of bullets and his powder horn. His heart, he realized, was beating only very slightly faster.

He saw Derkhan readying herself. She drew her two pistols and checked them, her eyes cold.

On the roof’s plateau, forty feet below, a little troop of dark-uniformed figures had appeared. They ran nervously between the outcroppings of architecture, their pikes and rifles rattling. There were perhaps twelve of them, their faces invisible behind their sheer reflective helmets, their segmented armour flapping against them, subtle insignia displaying rank. They spread out, came at the gradient of roofs from different angles.

“Oh dear Jabber,” swallowed Isaac. “We’re fucked.”

Five minutes, he thought in despair. That’s all we need. The fucking moths won’t resist this, they’re coming here already, couldn’t you have taken a little longer?

The dirigibles still prowled closer and closer, sluggish and ineluctable.

The militia had reached the outer edges of the tumbling slate hill. They began to climb, keeping low, ducking behind chimney stacks and dormer windows. Isaac stepped back from the edge, keeping them out of sight.

The Weaver was tracing its index finger through the water on the roof, leaving a trail of scorched dry stone, drawing patterns and pictures of flowers, whispering to itself. Andrej’s body spasmed as the current rocked him. His eyes wavered unnervingly.

“Fuck!” shouted Isaac, in despair and rage.

“Shut up and fight,” hissed Derkhan. She lay down and peered carefully over the edge of the roof. The highly trained militia were frighteningly close. She aimed and fired with her left hand.

There was a snapping explosion that seemed muffled by the rain. The closest officer, who had scaled nearly halfway up the slope, staggered back as the ball struck his armoured breast and ricocheted into the darkness. He teetered momentarily on the edge of his little roof-step, managed to right himself. As he relaxed and stepped forward, Derkhan fired her other gun.