Nkata parked illegally at the south end of Gabriel’s Wharf and put a police placard in the window. Turning up the collar of his coat against the rain, he strode into the wharf area, where the overhead lights made a cheerful crisscrossing pattern above him and the owner of the bicycle rental shop was wisely wheeling his wares indoors.

At Crystal Moon, it was Gigi this time and not her grandmother who was perched on a stool, reading behind the till. Nkata approached her and showed his police identification. She didn’t look at it, however. Instead, she said, “Gran told me you’d probably be back. She’s good that way. A real intuitive. In another time, she’d’ve been done for a witch. Did the agrimony work?”

“Not sure what I’m meant to do with it.”

“Is that why you’re back, then?”

He shook his head. “Wanted to have a word about a bloke called Kilfoyle.”

She said, “Rob?,” and closed her book. It was, he saw, one of the Harry Potters. “What about Rob?”

“You know him, then?”

“Yeah.” She said the word on two notes, a combination of confirmation and question. She looked wary.

“How well?”

“I’m not sure how I’m meant to take this,” she said. “Has Rob done something?”

“He buy stuff here?”

“Occasionally. But so do lots of other people. What’s this about?”

“What’s he buy off you, then?”

“I don’t know. He hasn’t been in in a while. And I don’t write down what people buy.”

“But you know he bought something.”

“Because I know him. I also know that two of the waitresses from Riviera Restaurant have made purchases as well. So have the head cook at Pizza Express and a collection of shop assistants from the wharf. But it’s the same as for Rob: I don’t recall what they bought. Except for the bloke at Pizza Express. He wanted a love potion for a girl he met. I remember that because we got into the whole love thing.”

“Know him how?” Nkata asked her.

“Who?”

“You said you know Kilfoyle. I’m wondering how.”

“You mean is he my boyfriend or something?” Nkata could see the colour deepen round the hollow of her throat. “No. He isn’t. I mean, we had a drink once, but it wasn’t a date. Is he in some sort of trouble?”

Nkata didn’t reply to this. It had always been a long shot, anyway, that the owner of Crystal Moon would remember what someone had bought. But the fact that Kilfoyle had indeed made a purchase gave the investigation grist to move forward, which was what they needed. He told Gigi that he appreciated her help and he gave her his card and told her to phone should she remember anything particular about Kilfoyle that she thought he should know. He realised that chances were good she’d hand over the card to Kilfoyle himself the next time she saw him, but he didn’t see that as a problem. If Kilfoyle was their killer, the fact that the cops were on to him would surely slow him down. At this point, that was nearly as gratifying as nabbing him. They had enough victims on their hands already.

He headed for the door, where he paused to ask another question of Gigi. “How’m I meant to use it, then?”

“What?”

“The agrimony.”

“Oh,” she said. “You burn or anoint.”

“Meaning?”

“Meaning: Burn the oil in her presence or anoint her body with it. I take it it’s a her we’re talking about?”

Nkata thought about and then dismissed the likelihood of his being able to accomplish either task. But he also thought about the serial killer: burning and anointing. He was doing both. He thanked Gigi and left the shop. He went next door to Mr. Sandwich.

The little eatery was closed for the day, and the sign said that its hours of business were from ten till three. He looked through the windows but could make nothing out in the semidarkness save the counter and, on the wall behind it, a list of sandwiches and their prices. There was nothing more to be gained in this spot, he decided. It was time to go.

But he didn’t head homeward. Instead, he felt himself compelled to drive yet another time in the general direction of the Oval, weaving over to Kennington Park Road as soon as he was able to do so. He parked again in Braganza Street, but rather than wait for her or enter Doddington Grove Estate to see if she was already home, he walked up to the dispirited patch of green that was Surrey Gardens. From there, he headed into Manor Place, a spot still trying to make a choice between decrepitude and renaissance.

He hadn’t been to her shop since November, but there was no way he could have forgotten where it was. He found her within, just as she’d been the last time he visited. She was at a desk at the back, her head bent over what looked like an accounts book. She had a pencil in her mouth, which made her look vulnerable, like a schoolgirl having trouble doing her sums. When she glanced up as he entered and the buzzer went off, though, she looked adult enough. And equally unfriendly. She set her pencil down and closed the book. She came to the counter and made sure, it seemed, that it stood like a bulwark between them.

He said, “A black boy was killed this time. His body got dumped near London Bridge Station. We got an ID on an earlier boy ’s well. Mixed race, he was. From Furzedown. That’s two boys south of the river now, Yas. Where’s Daniel?”

She said, “If you think-”

He cut her off impatiently. “Yas, Daniel have anything to do with a group of kids meeting up at Elephant and Castle?”

“Dan doesn’t do gangs,” she protested.

“Isn’t a gang, this, Yas. This’s an outreach group. They offer kids activities, kids at…kids at risk.” He hurried on. “I know. I know you’ll say Dan i’n’t at risk, and I’m not here to argue that. The group’s called Colossus, though, and I need to know. You ever talk to them about seeing to Dan after school? While you’re still working? Giving him a place to go?”

“I don’t let Dan up at Elephant and Castle.”

“And he never said Colossus to you?”

“He never…Why’re you doing this?” she demanded. “We don’t want you round us. You’ve done enough.”

She was getting agitated. He could see as much from the rise and fall of her breasts beneath her jersey. It was cropped like all the jerseys he’d ever seen her wear, showing off her smooth stomach, which was flat like a palm. She’d had her navel pierced, he saw. A bit of gold glittered against her skin.

His throat felt dry, but he knew there were things that he had to say to her, no matter how she was likely to receive them. He said, “Yas”-and he thought, What is it about the sound of her name?-“Yas, would you’ve rather not known what was going on? She was cheating on you, had been from the first, and you got to admit that no matter what you think of me.”

“You di’n’t have the right-”

“Would you rather’ve been kept in the dark about her? What good’s that supposed to do, then, Yas? And you and I know you’re not bent like that anyways.”

She pushed away from the counter. “That all? Cos if it is, I got work needs finishing before I go home.”

“No,” he returned. “Not all. There’s this. What I did was right and you know it somewhere.”

“You-”

“But,” he continued, “how I did it was wrong. And-” He’d come to the hard part now, the tell-the-truth part, when he didn’t want to admit that truth even to himself. But he plunged forward. “And why I did it, Yasmin. That was wrong ’s well. And it was wrong that I lied to myself about why I did it too. And I’m sorry for all of it. I’m dead sorry. I want to make things right.”

She was silent. There was nothing that could be called kind in her stare. A car pulled up to the kerb outside and her eyes flicked to it, then back to him. “Then stop using Daniel,” she said.

“Using…? Yas, I’m-”

“Stop using Daniel to get to me.”

“Tha’s what you think?”

“I don’t want you. I had a man. I married him, an’ every time I look in the mirror I get to see what he did to me an’ I get to think what I did back to him an’ I’m never going to that place again.”