The Marigold's door stood open an inch, which was an inch more than Bunmi ever left it.

Sefa stopped on the bottom rung of the ladder. The noon heat lay across the Bone Quay like a hand, and the barges ticked and pinged as the iron roofs expanded. Somewhere down the row a radio was playing a football commentary. Somewhere else a child was being told not to. It was all very ordinary, and the hair on her arms stood up.

"Bunmi?"

No answer. She pushed the door with two fingers.

The kitchen was exactly as she had left it, which was the first thing she checked, and the second thing she hated herself for checking. The stove was cold. The plantain plate was empty. The radio was off. The paper crown from Barge Two lay on the table beside a half-drunk mug, still faintly warm to the touch.

The biscuit tin was gone.

She had hidden it on the shelf, behind the damp paperbacks, behind a dictionary of nautical terms that nobody in forty years had ever opened. She went to the shelf, though she knew. There was a clean rectangle in the dust where it had stood. A small paper square lay at the edge, torn from the back of a school exercise book, written in pencil in a hand that wandered uphill.

*CHIEF FORGER. Bunmi went to the chapel to see Bro Ansgar. I was NOT to touch the tin but I heard her say it was not safe here with everyone coming and going so I took it to hide it BETTER. Do not worry. I know a place the bus did not know. Back by 3. Signed, Deputy P.*

Underneath, in smaller letters: *I did not eat all the dough. 3 pieces left. They are yours.*

She sat down hard on Bunmi's bunk. The springs complained. There were three pieces of fried dough, slightly squashed, on a saucer on the pillow, carefully arranged.

She ate one of the pieces of dough, because it was there, and because the small plain act of chewing seemed to be the only thing in the room she could still be sure of. It was cold, and chewy, and a little too salty. Pico had always liked it that way. She found she was smiling, and then that she was not.

She had been in this room a thousand times. It was a hull full of small certainties: the smell of palm oil, the blue boiler suit on its peg, the photograph of the brine boat with the woman at the wheel. She had never looked at that photograph properly. She did now. The woman in the captain's cap was thirty, maybe thirty-five, with a square brown face and a cigar in the corner of her mouth, laughing at whoever was holding the camera. Behind her on the deck, half cut off at the edge of the frame, stood two other figures: a tall, thin girl in a headscarf with a bright, shy, ink-stained smile, and a broader girl with her arms folded.

The broader girl wore a bracelet on her left wrist.

The door banged.

"There you are," said Bunmi, from the threshold. "The whole quay's talking. Captain Vosk's car took you off the Hall steps like you were the Duke of somewhere. Everyone filmed it. Rosalind has put it on the group chat. She's put little flames on it."

She was out of breath. She was holding a canvas bag in one hand and her phone in the other, and her face was grey, the careful grey of a woman who has been walking fast in the heat to avoid thinking. She saw Sefa's expression, and the note in her hand, and then the picture on the wall, and she stopped talking.

"Where's Pico?"

"I don't know."

"Where is the tin?"

"He's taken it," said Sefa. "To hide it better. He says."

Bunmi shut her eyes.

"I told that boy," she said. "I told him in plain words."

"He's eleven."

"I know how old he is." The canvas bag hit the table with a thump. "I went to the chapel for twenty minutes. Twenty minutes. I wanted to see what Ansgar had written in his book before it got into the wrong hands. I left him with a plate. I thought, he's eaten, he's safe, he's got a crown."

"Bunmi."

"What."

"Who's that?"

Sefa lifted the photograph from its nail and held it out. Her hand did not shake. It had gone past shaking into a kind of deep, cold stillness, like the stillness of a pan at noon.

Bunmi looked at it. She looked at the photograph for what felt like an hour.

"That's the Marigold," she said.

"I know the boat."

"It's the summer of the big harvest. Twenty-nine years ago. We hauled eleven thousand tons."

"I know the boat, Bunmi." She put her finger on the thin girl in the headscarf. "That's Mama."

"Yes."

"And that's Haldis."

The radio down the quay burst into a roar of cheering and fell away.

"Yes," said Bunmi.

"She told me this afternoon. She sat in her office and told me they were girls on the pans together. She said it like it was a small thing. Like it didn't matter. I think I'd have found it easier if she had lied." She took a breath and put it on a table somewhere out of reach. "You have never mentioned her. In twenty-six years. You have told me about Mama's temper and Mama's hands and Mama's terrible singing. You have never once said she had a friend."

"They fell out."

"When?"

Bunmi sat down. She did it as she had done it before, with great deliberation, easing one heavy bone at a time into the chair, and when she was down she covered her face with both hands, and Sefa saw her shoulders rise and fall.

"I swore on the keel," she said, into her palms. "I swore not to tell you what I told you. I have kept that. I have lain awake over it for two years. But I did not swear to hide what you can see with your own eyes, and I am damned if I'll sit here while a child works it out from a photograph." She lowered her hands. Her eyes were red-rimmed and absolutely dry. "When I said I held her hand. When I said she died at dawn on the hold of Barge Nine. That is true. Every word."

"And?"

"There was someone else on the deck."

The boards creaked. A gull screamed once overhead and was gone.

"I didn't see her arrive," Bunmi said. "I was below, at the pump. I came up when I heard Anwen call. She was lying under the mast with her arm gone white to the shoulder, and she was holding on to my hand as if I were the last rope on the ship. And she looked past me, and she said, 'Haldis.' Just that. Not angry. Not afraid. Like a woman who has been waiting for a particular knock on the door and has finally heard it." Her voice cracked. "And I turned round. And the Brine-Master of Tuzlag was standing at the rail with a little glass bottle in her hands and her face wet."

Sefa heard herself say, "What was in the bottle?"

"I don't know." The old woman looked at her. "I swear to you I don't. I have never known. But she took something from your mother's arm that morning, Sefa, with your mother's permission, and she has kept it ever since."

On the table, the paper crown lifted slightly in a draught from the door and settled again.

"She was kind to me," Bunmi said. "For thirty years. She paid for your school shoes when I couldn't. She sent a hamper every Christmas. She stood next to me at the stone every year and wept. I thought she was the best woman in Tuzlag. I thought I was the luckiest fool in the world to have her for a friend." She laughed, a small raw sound. "And all that time she knew exactly how your mother died, and who had been in the room."

Sefa put the photograph down, carefully, on the blanket. She stood. She walked to the shelf and the clean rectangle in the dust, and she put her fingers in it as if it were a footprint.

"Pico," she said. "He's at the Hall. Or on his way. She told him he could have a bed."

"Child, he said he'd be back by three."

"It's half past one."

"Then we've got an hour and a half."

"And a tin full of my life under his arm." Sefa pulled her phone out of the lining of her coat. She had not switched it on since morning, and she held her thumb on the button for a long second, as one holds a breath before a dive.

"Don't," said Bunmi. "Not on the guild's signal. They'll see you're back on the net."

"They'll see it in a minute anyway. I need to know where he is."

"Then use the old way. Walk up and ask."

"Bunmi, he's eleven. I'm not going to walk anywhere that he's already gone ahead of me." She said it more roughly than she meant. "I'll give them thirty seconds of signal. Then I'll turn it off."

The old woman said nothing, but she crossed the kitchen and stood at Sefa's shoulder, a solid warm presence smelling of palm oil and sweat and salt, close enough that their sleeves touched. Not a word of apology. It was how Bunmi did it. It was how she had always done it.

The screen lit. The logo of the network crossed it in blue. Then it filled, all at once, with seventy-three unread messages, a missed call from a number she didn't know, and a single notification across the top, bright and cheerful and perfectly designed, in a font she had seen on a thousand posters.

*BRINEBANK: Welcome, Pico Anwar! Your bed in Hostel 2 is ready. Tap here to set your locker code.*