She smiles, knowing he won’t desert her. But he’s right to be nervous: all the way in they had been pushing against the grain of evacuation. It was like swimming upstream, buffeted by the outward flow of countless ships. By the time they reached orbit, the transit stalks had already been blockaded: the authorities weren’t allowing anyone to ride them down to the surface. It had taken bribery and guile to secure passage on a descending car. They’d had the compartment to themselves, but the whole thing—so her companion had said—had smelt of fear and panic; human chemical signals etched into the very fabric of the furniture. She was glad she didn’t have his acuity with smells. She is frightened enough as it is: more than she wants him to know. She had been even more frightened when the Nestbuilders followed her into the system. Their elaborate spiral-hulled ship—fluted and chambered, vaguely translucent—is one of the last vessels in orbit. Do they want something of her, or have they just come to spectate?

She looks out to sea again. It might be her imagination, but the glowing smudges appear to have increased in number and size; less like a fleet of galleons below the water now than an entire sunken metropolis. And the smudges seem to be creeping towards the seaward end of the jetty. The ocean can taste her: tiny organisms scurry between the air and the sea. They seep through skin, into blood, into brain.

She wonders how much the sea knows. It must have sensed the evacuation: felt the departure of so many human minds. It must have missed the coming and going of swimmers, and the neural information they carried. It might even have sensed the end of the shepherding operation: two or three small chunks of former moon have already splashed down, although nowhere near these islands. But how much does it really know about what is going to happen? she wonders.

She issues a command to the butterflies. A regiment detaches from her sleeve, assembling before her face.