Imelda Reyes-Whitlock lived on the third floor of a building she owned, above a bakery she also owned, and she answered the door in a cardigan the colour of old tea and a pair of reading glasses pushed up into hair like white wire.

"Bread," she said, taking the bag. She weighed it in her hand. "Day-old."

"It's from your bakery."

"Then I know exactly how old it is." She stepped aside. "In, mija. Wipe your feet. Mind the cat, he's got opinions."

The kitchen was small, yellow and over-warm, and smelled of cumin and onions and, faintly, to a nose that could not have told Nadia but would have told anybody else, of a very old wolf: smoke, wet slate, something sweet gone slightly to rust. A radio muttered a football match from a shelf. On the table sat two plates of lentils with a fried egg on each, a bottle of something clear and unlabelled, and a stack of paper forms Imelda had been signing with a pen that skipped.

Nadia sat. The cat, a vast grey tom the size of a hearth rug, regarded her, then climbed onto her lap without apology.

"He likes you," said Imelda. "He likes people he can't smell. It's restful for him." She poured two glasses. "Eat."

They ate. Imelda ate the way she did everything, with focus and no waste. She asked about Toby's mother's knee. She asked about Nadia's brother, Mateo, three years into a degree on the Strata, a boy who sent money back down in the opposite direction by accident, because he didn't understand the maths. She said nothing about Braid, or the auditor, or the man standing under the laundromat sign, and Nadia's lentils turned to wet sand in her mouth.

"You want to ask," said Imelda at last, setting down her fork.

"I'd like to know how much you know."

"How much I know." Imelda looked at the ceiling as if the answer lay in a crack. "I know that for two years a girl in my building has been running a trade that makes people very happy and very frightened. I know she charges four thousand a pair. I know the Floor Tenancy has taken, in rent, nothing more than it always takes, and that I have never asked to see what's on the stove." She leaned back. "I also know that this afternoon, a man in good shoes walked down my street behind my tenant, looking like he'd swallowed a ruler. He's Registry. He has an Assay badge on a lanyard he forgot to put away. And you came to my table with that look on your face. So. Tell me about him."

Nadia told her.

It took longer than she meant. She told her about the clean note and the lift, about the swab, about the shoulder on the chromatogram. She did not say *father* until she had to. When she said it, the radio filled the silence with someone scoring.

Imelda took off her glasses and rubbed the bridge of her nose.

"Pablo," she said.

"You knew."

"I knew your father forty years. I didn't know it was in his notebooks." She said it flatly, then looked at Nadia properly, and the look was not the one reserved for tenants. "That's a lie. I knew he'd done a job. Once. Toward the end."

The cat shifted. Nadia kept very still beneath him.

"Three years ago," said Imelda, "he came to me. The clinic was bleeding. The licence board had given him ninety days, and he owed me six months' rent and the fire-safety bond, and he owed other people a good deal more. He'd stopped sleeping. You'd stopped speaking to him, I think. A year by then."

"Fourteen months." She heard her own voice, level and technical. "We had an argument about money. I said some things."

"Everyone says things." Imelda's mouth bent. "He came to me and said, 'Imelda, I have a way out and I don't like it.' I said, 'Pablo, you make medicine. What other way is there?' And he said there was a Rim family who needed a bond that wouldn't be questioned. Two people who couldn't pass the nose and had a great deal to lose. He said he'd found a way to make the third note. By chemistry. By hand."

Nadia put her glass down, carefully, because her fingers had stopped being entirely her own.

"He did it once," Imelda said. "I held the money. A quarter of a million, cash, delivered in a hatbox by a young woman with beautiful manners who said her name was nothing. He paid every debt he owed me and half of those he owed others. He said he would never touch it again. He said it was a bad piece of work and he'd done it for a good reason." She picked up the bottle, put it down. "And six weeks after the job, he was dead on his own clinic floor."

"A stroke."

"That's what the certificate says."

"Imelda."

"I'm not saying. I'm an old woman who runs a bakery. I'm saying he made one bond, and he was frightened of it, and then he wasn't alive." Her hands lay flat on the table, spotted and strong. "Then two years ago, you open a lab above my laundromat and you start making a thing that smells exactly like what he made. I didn't ask. I thought, the apple fell. I didn't think it had fallen from a tree with something in the roots."

The football match went to the advertisements. A jingle for a loan app. Neither of them moved.

"The woman with the hatbox," Nadia said. "A young woman. Beautiful manners. What did she look like?"

"Tall. Clean. Pale linen coat." Imelda shut one eye, remembering. "She had a ring on her thumb, a flat gold band, the kind you wear when your family's been wearing the same one for six hundred years. Rim, no question."

"A ring."

"I'm not telling you whose, because I don't know, and if I guessed, I'd be spreading a thing around that could get a girl killed, and I've done enough burying." She held Nadia's eyes. "But you should know that if that bond is the one your auditor is wearing, then whoever bought it had a reason to want the man who made it quiet. And his daughter's lab is the only other place in this city where the recipe lives."

The kitchen was very warm. The cat purred. Nadia understood, with horrible calm, that she was not in trouble with the Registry. She was in the second kind of trouble, the sort that arrived through a window.

"What do I do?"

"What you do," Imelda said, "is stop selling, tonight. Every client, every vial, every hour. You close the lab, you burn the book, and you let your Toby go to his mother's for a month."

"I can't. There's a list. People are waiting, there are weeks on the schedule, I owe Dad's loan sharks the last of the—"

"You owe my Tenancy nothing. He paid me off." A pause. "You owe others. I know. I carry that." Her voice dropped to its gravel floor. "But you are twenty-nine, mija, and you are the last place where the answer sleeps. Not the Registry's nose. Not your auditor, though he might do you good. *Your own life.* Sell nothing till you know who bought him."

"That's the thing. The auditor wants to know who sold his bond, not who bought it."

"Then give him both," said Imelda, "and make him pay for the information. A wolf in the Registry who owes you is worth a block of flats."

Nadia laughed, because the alternative was something else. She stroked the cat. His fur was thick, warm, and smelled of nothing she could name.

"There's one more thing," Imelda said, getting up to clear the plates. "The Assayer who died in Glassrow. Wren Castellanos-Boyd. I knew her mother. She'd been writing to the Director about *unlicensed doses at the Assay*. Not outside it. Inside." She turned the tap on and spoke over the water. "Somebody at that office has been letting your father's note through the nose for years. You are not the only one in the room with the recipe."

The water ran.

Nadia sat with a sleeping cat and a cooling egg, and a new, cold certainty that the person who had killed her father, if anyone had, was still walking around the Strata in good shoes.

She was lifted off the stool by the weight of the evening. Imelda did not hug her. She pressed a foil parcel of leftover lentils into her hands, said, "Eat it cold, don't thank me," and shut the door.

Soledad Aguirre-Tan was sitting on the bottom step of the stairwell with her bicycle helmet in her lap, picking at a scab on her knuckle.

"Nads. There you are." Sol was twenty-seven, brown and quick and wiry, with a courier's thighs and a laugh she could not keep down in a church. Tonight she wasn't laughing. "I did a run to Glassrow this afternoon. Dropped the second dose to the Okonkwo-Reyes couple. And on the way back, three different people stopped me at three different lights."

"Stopped you."

"Asked if I knew the Chandler. Asked it nice, like a joke. One of them was a bike-share kid, one was a woman at a kebab van, one was a man I'd swear was a landlord." Sol turned the helmet over in her hands. "Fifty thousand, Nadia. For a name. Cash, by the end of the week. It's on the Chirrup boards already, in the weird corners. Somebody wants you bad and they've got money to burn."

Nadia stood on the third step with a foil parcel of lentils and felt the Floor, the whole loud brown beautiful Floor, tip very slightly under her feet.

"Did you tell them anything?"

"I told them I deliver laundry," said Sol. "I've been telling people I deliver laundry for two years. I'm very good at it. I'm a *beautiful* liar." A flash of the old grin, gone again. "But Nads, I'm also a gambler. And I know what it looks like when the odds just changed.