“Maybe Jimmy spotted it, snooping around Ebury Street, trying to collect his blackmail money,” suggested Robin, but Strike was now frowning.

“But that’s back to front. If she found out about the blackmailable offense when she was a cleaner, her employment must’ve pre-dated Jimmy trying to collect money.”

“All right, maybe Jimmy didn’t tip her off. Maybe they found out he wanted a cleaner while they were trying to dig dirt on him in general.”

“So they could run an exposé on the Real Socialist Party website?” suggested Barclay. “That’d reach a good four or five people.”

Strike snorted in amusement.

“Main point is,” he said, “this piece of paper’s got Jimmy very worried.”

Barclay speared his last pork ball and stuck it in his mouth. “Flick’s taken it,” he said thickly. “I guarantee it.”

“Why are you so sure?” asked Robin.

“She wants somethin’ over him,” said Barclay, getting up to take his empty plate over to the sink. “Only reason he’s keepin’ her around is because she knows too much. He told me the other day he’d be happy tae get shot of her if he could. I asked why he couldnae just dump her. He didnae answer.”

“Maybe she’s destroyed it, if it’s so incriminating?” suggested Robin.

“I don’t think so,” said Strike. “She’s a lawyer’s daughter, she’s not going to destroy evidence. Something like that paper could be valuable, if the shit hits the fan and she decides she’s going to cooperate with the police.”

Barclay returned to the sofa and picked up his beer.

“How’s Billy?” Robin asked him, getting started at last on her own cooling meal.

“Poor wee bastard,” said Barclay. “Skin and bone. The traffic cops caught him when he jumped a Tube barrier. He tried tae batter them, ended up bein’ sectioned. The doctors say he’s got delusions o’ persecution. At first he thought he was bein’ chased by the government and the medical staff were all part o’ some giant conspiracy, but now he’s back on his medication he’s a wee bit more rational.

“Jimmy wanted tae take him home there and then, but the docs werenae gonna let that happen. What’s really pissin’ Jimmy off,” said Barclay, pausing to finish his can of Tennent’s, “is Billy’s still obsessed wi’ Strike. Keeps askin’ for him. The doctors think it’s part o’ his delusion, that he’s latched ontae the famous detective as part of his fantasy, like: the only person he can really trust. Couldnae tell them he and Strike have met. Not wi’ Jimmy standin’ there telling them it’s all a load o’ pish.

“The medics don’t want anyone near him except family, and they’re no keen on Jimmy any more, neither, not after he tried tae persuade Billy he’s well enough to go home.”

Barclay crushed his beer can in his hand and checked his watch.

“Gotta go, Strike.”

“Yeah, all right,” said Strike. “Thanks for staying. Thought it would be good to have a joint debrief.”

“Nae bother.”

With a wave to Robin, Barclay departed. Strike bent to pick up his own beer off the floor and winced.

“You all right?” asked Robin, who was helping herself to more prawn crackers.

“Fine,” he said, straightening up again. “I did a lot of walking again today, and I could have done without the fight yesterday.”

“Fight? What fight?” asked Robin.

“Aamir Mallik.”

“What!”

“Don’t worry. I didn’t hurt him. Much.”

“You didn’t tell me the argument got physical!”

“I wanted to do it in person, so I could enjoy you looking at me like I’m a complete bastard,” said Strike. “How about a bit of sympathy for your one-legged partner?”

“You’re an ex-boxer!” said Robin. “And he probably weighs about nine stone soaking wet!”

“He came at me with a lamp.”

“Aamir did?”

She couldn’t imagine the reserved, meticulous man she had known in the House of Commons using physical violence against anyone.

“Yeah. I was pushing him about Chiswell’s ‘man of your habits’ comment and he snapped. If it makes you feel any better, I don’t feel good about it,” said Strike. “Hang on a minute. Need a pee.”

He pulled himself awkwardly out of the chair and departed for the bathroom on the landing. As she heard the door close, Strike’s mobile, which was charging on top of the filing cabinet beside Robin’s desk, rang. She got up to check it and saw, through the cracked and sellotaped screen, the name “Lorelei.” Wondering whether to answer it, Robin hesitated too long and the call went to voicemail. Just as she was about to sit down again, a small ping declared that a text arrived.

If you want a hot meal and a shag with no human emotions involved, there are restaurants and brothels.

Robin heard the bang of the bathroom door outside and stumbled hastily back to her chair. Strike limped back inside the room, lowered himself into his chair and picked up his noodles.

“Your phone just rang,” said Robin. “I didn’t pick up—”

“Chuck it over,” said Strike.

She did so. He read the text with no change of expression, muted the phone and put it in his pocket.

“What were we saying?”

“That you didn’t feel good about the fight—”

“I feel fine about the fight,” Strike corrected her. “If I hadn’t defended myself I’d have a face full of stitches.”

He pronged a forkful of noodles.

“The bit I don’t feel great about is when I told him I know he’s been ostracized by his family, barring one sister who’s still talking to him. It’s all on Facebook. It was when I mentioned his family dropping him that I nearly got my head taken off with a table lamp.”

“Maybe they’re upset because they think he’s with Della?” suggested Robin as Strike chewed his noodles.

He shrugged and made an expression indicative of “maybe,” swallowed, and said, “Has it occurred to you that Aamir is literally the only person connected with this case who’s got a motive? Chiswell threatened him, presumably with exposure. ‘A man of your habits.’ ‘Lachesis knew when everyone’s time was up.’”

“What happened to ‘forget about motive, concentrate on means’?”

“Yeah, yeah,” said Strike wearily. He set aside his plate, from which he had eaten nearly all the noodles, took out his cigarettes and lighter, and sat up a little straighter. “OK, let’s focus on means.

“Who had access to the house, to anti-depressants and helium? Who knew Jasper Chiswell’s habits well enough to be sure he’d drink his orange juice that morning? Who had a key, or, who would he have trusted enough to let in in the early hours of the morning?”

“Members of his family.”

“Right,” said Strike, as his lighter flared, “but we know Kinvara, Fizzy, Izzy and Torquil can’t have done it, which leaves us with Raphael and his story of being ordered down to Woolstone that morning.”