This was the third message Matthew had left that day.

Urgent situation, my arse.

Tom had probably found out that his fiancée and his good friend had been sleeping together. Maybe Tom was threatening to call Robin, or drop in on the office in Denmark Street, to find out how much she knew. If Matthew thought that constituted an “urgent situation” to Robin, who was currently standing beside multiple pictures of a drugged and suffocated government minister, he was wrong. With an effort, she refocused on the conversation in the incident room.

“… the necklace business,” Layborn was saying to Strike. “Far more convincing story than the one he told us. All that guff about wanting to stop her hurting herself.”

“It was Robin who got him to change his story, not me,” said Strike.

“Ah—well, good work,” Layborn said to Robin, with a hint of patronage. “I thought he was an oily little bastard when I took his initial statement. Cocky. Just out of jail, and all. No bloody remorse for running over that poor woman.”

“How are you getting on with Francesca?” Strike asked. “The girl from the gallery?”

“We managed to get hold of the father in Sri Lanka and he’s not happy. Being quite obstructive, actually,” said Layborn. “He’s trying to buy time to get her lawyered up. Bloody inconvenient, the whole family being abroad. I had to get tough with him over the phone. I can understand why he doesn’t want it all coming out in court, but too bad. Gives you a real insight into the mindset of the upper classes, eh, case like this? One rule for them…”

“On that subject,” said Strike, “I assume you’ve spoken to Aamir Mallik?”

“Yeah, we found him exactly where your boy—Hutchins, is it?—said he was. At his sister’s. He’s got a new job—”

“Oh, I’m glad,” said Robin inadvertently.

“—and he wasn’t overjoyed to have us turning up at first, but he ended up being very frank and helpful. Said he found that disturbed lad—Billy, is it?—on the street, wanting to see his boss, shouting about a dead child, strangled and buried on Chiswell’s land. Took him home with the idea of getting him to hospital, but he asked Geraint Winn’s advice first. Winn was furious. Told him on no account to call an ambulance.”

“Did he, now?” said Strike, frowning.

“From what Mallik’s told us, Winn was worried association with Billy’s story would taint his own credibility. He didn’t want the waters muddied by a psychotic tramp. Blew up at Mallik for taking him into a house belonging to the Winns, told him to turf him out on the street again. Trouble was—”

“Billy wouldn’t go,” said Strike.

“Exactly. Mallik says he was clearly out of his mind, thought he was being held against his will. Curled up in the bathroom most of the time. Anyway,” Layborn took a deep breath, “Mallik’s had enough of covering up for the Winns. He’s confirmed that Winn wasn’t with him on the morning of Chiswell’s death. Winn told Mallik afterwards, when he put pressure on Mallik to lie, he’d had an urgent phone call at 6 a.m. that day, which is why he left the marital home early.”

“And you’ve traced that call?” said Strike.

Layborn picked up the printout of phone records, rifled through them, then handed a couple of marked pages to Strike.

“Here you go. Burner phones,” he said. “We’ve got three different numbers so far. There were probably more. Used once, never used again, untraceable except for the single instance we got on record. Months in the planning.

“A single-use phone was used to contact Winn that morning, and two more were used to call Kinvara Chiswell on separate occasions during the previous weeks. She ‘can’t remember’ who called her, but both times—see there?—she talked to whoever it was for over an hour.”

“What’s Winn got to say for himself?” asked Strike.

“Closed up like an oyster,” said Layborn. “We’re working on him, don’t worry. There are porn stars who’ve been fucked fewer different ways than Geraint W—sorry, love,” he said, grinning, to Robin, who found the apology more offensive than anything Layborn had said. “But you take my point. He might as well tell us everything now. He’s screwed every which w—well,” he said, floundering once more. “What interests me,” he started up again, “is how much the wife knew. Strange woman.”

“In what way?” asked Robin.

“Oh, you know. I think she plays on this a bit,” said Layborn, with a vague gesture towards his eyes. “Very hard to believe she didn’t know what he was up to.”

“Speaking of people not knowing what their other halves are up to,” interposed Strike, who thought he detected a martial glint in Robin’s eye, “how’s it going with our friend Flick?”

“Ah, we’re making very good progress there,” said Layborn. “The parents have been helpful in her case. They’re both lawyers and they’ve been urging her to cooperate. She’s admitted she was Chiswell’s cleaner, that she stole the note and took receipt of the crate of champagne right before Chiswell told her he couldn’t afford her anymore. Says she put it in a cupboard in the kitchen.”

“Who delivered it?”

“She can’t remember. We’ll find out. Courier service, I shouldn’t wonder, booked on another burner phone.”

“And the credit card?”

“That was another good spot of yours,” admitted Layborn. “We didn’t know a credit card had gone missing. We got details through from the bank this morning. The same day Flick’s flatmate realized the card was gone, somebody charged a crate of champagne and bought a hundred quid’s worth of stuff on Amazon, all to be sent to an address in Maida Vale. Nobody took delivery, so it was returned to the depot where it was picked up that afternoon by someone who had the failed delivery notice. We’re trying to locate the staff who can identify the person who collected it and we’re getting a breakdown on what was bought on Amazon, but my money’s on helium, tubing and latex gloves.

“This was all planned months in advance. Months.”

“And that?” Strike asked, pointing to the photocopy of the note in Chiswell’s handwriting, which was lying on the side in its polythene bag. “Has she told you why she nicked it yet?”

“She says she saw ‘Bill’ and thought it meant her boyfriend’s brother. Ironic, really,” said Layborn. “If she hadn’t stolen it, we wouldn’t have cottoned on nearly so fast, would we?”

The “we,” thought Robin, was daring, because it had been Strike who had “cottoned on,” Strike who had finally cracked the significance of Chiswell’s note, as they drove back to London from Chiswell House.

“Robin deserves the bulk of the credit there, too,” said Strike. “She found the thing, she noticed ‘Blanc de Blanc’ and the Grand Vitara. I just pieced it together once it was staring me in the face.”

“Well, we were just behind you,” said Layborn, absentmindedly scratching his belly. “I’m sure we’d have got there.”