The arm and bow disappeared. Pengefinchess submerged again.

Derkhan turned her back on the river and headed back into the Council’s labyrinth.

She followed the trail of decaying cable through the twists of the junkyard scenery, into the Council’s presence. The avatar stood waiting by the diminished coil of rubber-swathed wire.

“Is the crossing successful?” he asked as soon as he saw her. He stumbled forwards, the cable that burst from his brainpan rattling behind him. Derkhan nodded.

“We’ve got to get things ready here,” she said. “Where’s the output?”

The avatar turned and indicated for her to follow him. He stopped for a moment and picked up the other end of the cable. He staggered under its weight, but he did not complain or ask for help, and Derkhan did not volunteer.

With the thick insulated wire under his arm, the avatar approached the constellation of rubbish that Derkhan recognized as the Construct Council’s head (with a slight unsettling jolt, as at a child’s book of optical tricks, as if an ink drawing of a young woman’s face had suddenly become a crone’s). It still lolled sideways, without any sign of life.

The avatar reached up over the grille that doubled as the Council’s metal teeth. Behind one of the enormous lights Derkhan knew were its eyes, a tangled knot of wire and tubing and rubbish burst out of a casing, in which the stuttering valves of some vastly complex analytical engine were working.

It was the first sign that the great construct was conscious. Derkhan thought she saw light glimmer faintly, waxing and waning, in the Council’s huge eyes.

The avatar pulled the cable into position beside the analogue brain, one of the network that made up the Council’s peculiar inhuman consciousness. He untwisted several of the thick wires in the cable, and in the explosion of metal from the Council’s head.

Derkhan looked away, sickened, as the avatar placidly ignored the way the vicious metal tore jagged holes in his hands, and sluggish, greying blood oozed fitfully out and over his decaying skin.

He began to link the Council to the cable, twisting finger-thick wires together into a conducting whole, snapping connections into sockets that sputtered with obscure sparks, examining the seemingly meaningless buds of copper and silver and glass that flowered from the Construct Council’s brain and from the rubber sheathing of the cable, picking some, twisting and discarding others, plaiting the mechanism into impossibly complex configurations.

“The rest is easy,” he whispered. “Wire to wire, cable to cable, at every junction throughout the city, that is easy. This is the only taxing part, here at source, to connect up correctly, to channel the exudations, to mimic the operation of the communicators’ helmets for an alternative model of consciousness.”

Yet despite the difficulty, it was still light when the avatar looked up at her, wiped his lacerated hands against his thighs, and said that he had finished.

Derkhan watched the little flashes and sparks that burst ominously from the connection with awe. It was beautiful. It glittered like some mechanical jewel.

The Council’s head-vast and still immobile, like a sleeping daemon’s-was linked to the cable with a knot of connective tissue, an elyctro-mechanical, thaumaturgic scar. Derkhan marvelled. Eventually she looked up.

“Well then,” she said hesitantly, “I’d best go and tell Isaac that…that you’re ready.”

With great sweeps of dirty water, Pengefinchess and her companion kicked their way through the eddying darkness of the Tar.

They stayed low. The bottom was barely visible as uneven darkness two feet below them. The cable unwound slowly from the great pile they had left at the bottom of the river, by the edge of the wall.

It was heavy, and they lugged it sluggishly through the filthy river.

They were alone in this part of the water. There were no other vodyanoi: only a few hardy, stunted fishes that skimmed nervously away at their approach. As if, thought Pengefinchess, anything in the whole of Bus-Lag could induce me to eat them.

Minutes passed and their hidden passage continued. Pengefinchess did not think of Derkhan or of what would happen that night, did not consider the plan on which she had eavesdropped. She did not evaluate its probable success. It was none of her concern.

Shadrach and Tansell were dead, and it was time for her to move on.

In a vague way, she wished Derkhan and the others luck. They had been companions, though very briefly. And she understood, in a lax fashion, that there was a great deal at stake. New Crobuzon was a rich city, with a thousand potential patrons. She wanted it to remain healthy.

Ahead of her the slick darkness of the approaching riverwall welled up. Pengefinchess slowed. She hovered in the water and hauled in some slack on the cable, enough to raise it to the surface. Then she hesitated a moment and kicked up. She indicated the male vodyanoi should follow her and she swam up through gloom towards the fractured light that marked out the Tar’s surface, where a thousand rays of sun seeped in all directions through the little waves.

They broke the surface together, and kicked the last few feet into the shadow of the riverwall.

Rusting iron rings were driven into the bricks, creating a rough staircase up to the riverside walk above them. The sound of cabs and pedestrians sank down around them.

Pengefinchess adjusted her bow slightly, making it more comfortable. She looked at the surly male and spoke to him in Lubbock, the polysyllabic guttural language of most of the eastern vodyanoi. He spoke a city dialect, which had been bastardized with human Ragamoll, but they could still understand each other.

“Your companions know to find you here?” Pengefinchess enquired brusquely. He nodded (another human trait the city vodyanoi had adopted). “I am done,” she announced. “You must hold the cable alone. You can wait for them. I am leaving.” He looked at her, still surly, and nodded again, raised his hand in a choppy motion which might have been some kind of salute. Pengefinchess was amused. “Be fecund,” she said. It was a traditional farewell.

She sank under the surface of the Tar and powered herself away.

Pengefinchess swam east, following the course of the river. She was calm, but a rising excitement filled her up. She had no plans, no ties. She wondered, suddenly, what she would do.

The current took her towards Strack Island, where the Tar and Canker met in a confused current and became the Gross Tar. Pengefinchess knew that the submerged base of the Parliament’s island was patrolled by vodyanoi militia, and she kept her distance, branching away from the pull of the water and bearing sharply north-west, swimming upstream, transferring into the Canker.

The current was stronger than the Tar’s, and colder. She was exhilarated, briefly, until she entered a sluice of pollution.

It was the effluent from Brock Marsh, she knew, and she kicked quickly through the murk. Her undine familiar trembled against her skin as she approached certain random patches of water, and she would arc away and pick another route through the fouled river by the magicians’ quarter. She breathed the disgusting liquid shallowly, as if she might avoid contamination that way.

Eventually the water seemed to thin. A mile or so upstream from the rivers’ convergence, the Canker grew suddenly more clear and pure.

Pengefinchess felt something almost like quiet joy.

She began to feel other vodyanoi pass her in the current. She kicked low, here and there felt the gentle outflow of tunnels that led up to some wealthy vodyanoi’s house. These were not the absurd hovels of the Tar, of Lichford and Gross Coil: there, sticky, pitch-coated buildings of palpably human design had simply been built in the river itself, decades ago, to crumble in unsanitary fashion into the water. Those were the vodyanoi slums.