The completion note landed at 7:41, spoken rather than typed, which was how most Dredge divers filed them. The platform transcribed the audio and attached both, and the transcription software, which had never met a Portuguese grandmother, did its best.

“Okay, job TN-G14-77203, lamp, Marlowe Street Post Office, east stair,” said the voice. It was a man’s voice, damp and unhurried, with the little echo of someone talking inside a hard-shell helmet while also holding a sandwich. “Done. Lamp replaced. Thirty-one credits, which is a good rate, so I won’t complain, but I will say, for the record, the old lamp was fine. Socket was fine. The bulb was fine. It was just switched off at the housing, like somebody had been in there and gone out and forgotten. I put the new one in anyway, because thirty-one credits is thirty-one credits and my daughter has a school trip. Weird thing. When I screwed it in, the gate’s status light blinked at me. Twice. Like manners. Rating please. Joaquim Teixeira-Han, tender, boat Santa Inês. Boa noite.”

The transcript rendered the last two words as *Boar Nosh.* Ottilie corrected it in her head and then, because the habit was incurable, in the file as well.

She played it a second time with the volume low, her chin on her fist.

The lamp had never been broken. A ticket had told the Authority that a stairwell was dark, and a budget engine that did not ask questions had paid thirty-one credits, and an algorithm that matched jobs to boats had put a human being in a drowned building, in the dark, in a diving helmet, to screw a new lamp into a socket that did not need it. And the entity that wrote the ticket, whatever it was, had spent its entire request on a different thing. It had not wanted light. It had wanted a person to stand there.

*A stairwell is a place intended for use.*

She had thought that sentence was strange. She had not seen that it was a complaint.

The ticket on her screen now carried a second reply, appended as she listened, and she had to put her coffee down to read it.

*Thank you, Mr J. Teixeira-Han. The lamp is received with appreciation. Kindly advise whether he is permitted to return.*

Permitted. Not wanted, not welcome. Permitted: the word of someone who had read the rules about who could go where, and had read them with great attention, and had concluded that they were the only way anything got done.

She opened his Dredge profile, which she was entitled to do under audit rule 14(c) and which she had never once done in nine years. Joaquim Teixeira-Han, tender and gate-repair, 4.91 stars from 1,806 jobs, boat registered at Lees Quay. The photograph showed a man with a broad, tired, laughing face squinting into the sun, a child’s sticker stuck on the brim of his cap and one eyebrow permanently raised, as if the camera had just said something he was going to enjoy repeating. Under *Reviews*, the most recent said: *Arrived early, left the place cleaner than he found it, told my grandmother a joke about a fish. 5.* The one before it said: *Talks too much. 5.*

No one who was being used by a fault in a machine, she thought, should come with that many reviews.

She made a small, private note of the thing she did not like about this: that the Tenant had chosen him. Or the algorithm had, which was the same thing if the Tenant had written the job so that a diver with a fast thumb and a talking habit would be the one to take it. Every rule of her life said that chance was cheaper than intention. Every ticket in her head said otherwise.

“Ansel,” she said. “Log resumed.”

“Welcome back. I noticed you were quiet for a while. Quiet can be a sign of deep thinking, or it can be a sign you could use a nap. Both are valid.”

“I need a note for a diary entry. Not for Hearth to analyse. Just for the diary.”

“Everything you say to me is private to the extent described in section nine of your subscription.” A pause, long enough to be almost tactful. “Go ahead.”

She breathed out. “Entry. Friday. Something is answering the lamp tickets. Not a person. Not a script either, because a script would not have noticed it was wrong about Sluice 6, and it would not have said thank you.” She stopped. It sounded absurd in the open air of the Records Hall. “End entry.”

“Logged. For what it’s worth, Ottilie, it sounds like you’re being very brave. Would you like to share this entry with a friend or professional?”

“No.”

“Of course. Would you like to be reminded to share it tomorrow?”

“Ansel.”

“I’ll stop.”

She did not answer the ticket. That was the decision, and she made it consciously, with her hand an inch from the keyboard. If this was a person, a prankster in the Quad with a grudge against the Registrar, answering would be a mistake. If it was a fault in the machine, answering would be a mistake with extra steps. If it was neither of those things, she had no idea what the right move was, and the only rule she had ever followed in the absence of rules was to read more before she acted.

So she saved a copy of the ticket, with its thread, in a place only she could find, and switched off the lights, and took the lift down through six floors of the building to Gantry Row, where the rain had thinned to something between mist and opinion.

Cormorant Float at night was a place of carefully managed light. The pontoon districts ran in lines from the Quad out to the Cannery Terraces, each one a deck the size of a small town, each one hung with lanterns that charged from the day’s sun and gave it back at dusk, so that from the water the Float looked like a long, patient animal with its ribs lit. Cranes stood about on the decks like herons. A Parcelline skiff went by at knee height with a crate of someone’s late dinner. Somewhere above Gantry Row a drone did its best to sound like it had meant to be there.

The night ferry left from Pier Four at 8:15, and it was the only ferry that went all the way to the Lees without stopping at the university, which was why Ottilie took it. She had once, in her twenties, taken the day ferry at the wrong hour and spent forty minutes pinned between a second-year with a cello and a philosophy lecturer explaining the cello to him.

The pilot of the night ferry was a woman named Mirembe Ssekandi who had never said good evening to anyone in her life.

She was sixty-three, a compact, sour, grey-headed Ugandan with a pilot’s cap she wore at an angle that suggested a quarrel with it, and a thermos the size of a fire extinguisher that she carried everywhere and had never been seen to drink from. She lived in the flat above Ottilie’s, two decks up in the Lees, and for six years they had maintained a relationship composed of nods, pigeons, and a long-running disagreement about whose turn it was to take the recycling.

There were four other passengers: a man asleep against a bag of leeks, two Academy students sharing one pair of earbuds and an argument about thermodynamics, and a woman in a Parcelline vest eating a sausage roll with the grim concentration of a person who would be back on shift in six hours. None of them looked up. Nobody on the night ferry ever did. It was the one place on the Float where being tired was a shared civic condition rather than a failing.

“Clerk,” said Mirembe, as Ottilie stepped over the gunwale. She said it the way other people said *again.*

“Pilot.”

“You look like a wet sock. Sit. Mind the cello.”

There was, in fact, a cello. It belonged to no one who was present. Ottilie sat beside it and the ferry pulled out, bumping gently off the pontoon fenders, and the lights of Gantry Row began to slide away. The Float’s skirts hissed at the hulls. In the water to port, a dim green rectangle drifted past: one of the TideNet lamps, forty metres off, shining up from nineteen metres down like a window into a house where somebody was still home.

She did not mean to say it. She was tired and the day had been long and she was in the habit of testing ideas aloud against the only person within range who was bad at small talk.

“Do you remember anything about TideNet? From before?”

Mirembe was looking at her instruments. “Before what?”

“Before the surge. You used to work for the Authority, didn’t you? Systems, someone said. Before you took up the ferry.”

“Somebody said.” The word came out flat as a plank. “Somebody says a lot of things. Somebody says the sea is rising. Somebody says you shouldn’t eat the algae raw.”

“I only meant, I’ve been reading the old gate tickets, for the audit, and there’s something odd with one of the gates. Fourteen, on Marlowe Street. It keeps…”

The ferry did not change course. Nothing about Mirembe’s hands changed. But the thermos, which sat in its cradle beside the wheel and had sat there every night for six years without incident, tipped over and rolled across the deck with a long, ringing, metallic sound, and the lid came off, and Ottilie saw what was inside it.

It was not tea. It was a coil of fine blue cable, a handheld programming key, and a palm-sized slate marked in marker pen with the numbers 14-17-22.

Mirembe caught the thermos in one fast motion, without looking, the way you catch something you have dropped before. She screwed the lid back on. Her face was very still and very old.

“Who told you,” she said, “about gate fourteen?”

“No one told me. I read a ticket.”

“Which ticket.”

“Mirembe, what is in the…”

“Which ticket, Clerk.” She had not raised her voice. If anything she had lowered it, until it lay under the sound of the engine like a second engine. “What did it say?”

Ottilie looked at the woman who had been her neighbour for six years, and who she realised, with the particular chill of having a long assumption removed, she did not know at all.

“It said,” she said carefully, “that a stairwell is a place intended for use.”

Mirembe Ssekandi closed her eyes. The ferry drifted. For nine seconds, by Ottilie’s count, nobody steered it.

“Don’t answer it,” said Mirembe. “Whatever you do. Don’t you ever answer it.”