For a long time there was only whispering and the faint noises of gulls and the waves. Everyone who stood in the bleak heat strained to hear something that they had not heard before, but they had no idea what they were waiting for. When it finally came it was a sound so monolithic that they felt it, deep below, resonating through the ships.

Bellis heard Uther Doul exhale, then he whispered "Now," his voice thick with emotion she did not recognize.

The deck of the Grand Easterly moved suddenly below their feet, with a cracking percussion.

Armada vibrated violently.

"The bridle, the chains," Doul said quietly. "They’re being lowered. Into the hole."

Bellis gripped the rail.

Below the water Tanner gasped, water rushing over his gills, as the vast pulleys turned and the restraining bolts on the harness were burst with explosive charges. In carefully choreographed sequence, displacing great tides of brine, the metal ring more than a quarter of a mile across, studded with cruel hooks and collars, began to descend.

It slid in stages through the water, reaching the limit of its freedom as each section of boat-long links ended. And then another charge would detonate, and huge gears would turn, and a few more hundred feet of metal would sink.

As each length of chain reached its end, the city above moved, and reconfigured a little, its dimensions shifting under the strain. The chains were so huge, they operated at a geographic scale, each weighty tug a seismic trauma. But Armada was buoyed by careful design and gas and thaumaturgy, and though the sudden jolts shook it as if in a high storm, and strained at those few wickerwork-and-rope bridges that were not uncoupled, and snapped them, they could not capsize the city.

"Jabber and fuck," Bellis shouted. "We have to get below!"

Doul held her, gripped her hard and kept her feet flat.

"I’ll not miss this," he said, "and I don’t think you should, either."

The city bucked appallingly; then, suddenly.

The bridle’s descent began to speed up. Tanner Sack realized he was shouting soundlessly, airlessly, his jaw biting out silent profanities at the sight. He was hypnotized by the scale of what he saw, the rapid disappearance of the huge harness into the absolutely dark sea. Seconds and minutes passed. The city stabilized a little and there was only the continuing unfolding of the great tethered chains, five lines of links descending into the hidden deeps.

Colonies of barnacles and limpets had scabbed the chains over generations, and as the links ripped free of the ships’ undersides, they sent clouds of dying shellfish into the abyss.

After many minutes had passed, Armada was almost still again, undulating very slightly with the last reverberations of the chain. Birds shunted mindlessly back and forth overhead. The huge weight of the metal settled. There was a tense expectancy.

And everyone held their breath, and nothing happened.