Robin arrived home just before 2 a.m. As she crept around the kitchen, making herself a sandwich, she noticed on the kitchen calendar that Matthew was planning to play five-a-side football later that morning. Accordingly, when she slipped into bed with him twenty minutes later, she set the alarm on her phone for eight o’clock before plugging it in to charge. As part of her effort to try and keep the atmosphere amicable, she wanted to get up to see him before he left.

He seemed happy that she’d made the effort to join him for breakfast, but when she asked whether he wanted her to come and cheer from the sidelines, or meet him for lunch afterwards, he declined both offers.

“I’ve got paperwork to do this afternoon. I don’t want to drink at lunchtime. I’ll come straight back,” he said, so Robin, secretly delighted, because she was so tired, told him to have a good time and kissed him goodbye.

Trying not to focus on how much lighter of heart she felt once Matthew had left the house, Robin occupied herself with laundry and other essentials until, shortly after midday, while she was changing the sheets on their bed, Strike called.

“Hi,” said Robin, gladly abandoning her task, “any news?”

“Plenty. Ready to write some stuff down?”

“Yes,” said Robin, hurriedly grabbing notebook and pen off the top of her dressing table and sitting down on the stripped mattress.

“I’ve been making some calls. First off, Wardle. Very impressed with your work in getting hold of that note—”

Robin smiled at her reflection in the mirror.

“—though he’s warned me the police won’t take kindly to us, as he put it, ‘clodhopping all over an open case.’ I’ve asked him not to say where he got the tip-off about the note, but I expect they’ll put two and two together, given that Wardle and I are mates. Still, that’s unavoidable. The interesting bit is that the police are still worried about the same features of the death scene as we are and they’ve been going deeper into Chiswell’s finances.”

“Looking for evidence of blackmail?”

“Yeah, but they haven’t got anything, because Chiswell never paid out. Here’s the interesting bit. Chiswell got an unexplained payment in cash of forty thousand pounds last year. He opened a separate bank account for it, then seems to have spent it all on house repairs and other sundries.”

“He received forty thousand pounds?”

“Yep. And Kinvara and the rest of the family are claiming total ignorance. They say they don’t know where the money came from or why Chiswell would’ve opened a separate account to take receipt of it.”

“The same amount Jimmy asked for before he scaled down his request,” said Robin. “That’s odd.”

“Certainly is. So then I called Izzy.”

“You’ve been busy,” said Robin.

“You haven’t heard the half of it. Izzy denies knowledge of where the forty grand came from, but I’m not sure I believe her. Then I asked her about the note Flick stole. She’s appalled that Flick might’ve been posing as her father’s cleaner. Very shaken up. I think for the first time she’s considering the possibility that Kinvara isn’t guilty.”

“I take it she never met this so-called Polish woman?”

“Correct.”

“What did she make of the note?”

“She thinks it looks like a to-do list, as well. She assumes ‘Suzuki’ meant the Grand Vitara, which was Chiswell’s. No thoughts on ‘mother.’ The one thing of interest I got from her was in relation to ‘blanc de blanc.’ Chiswell was allergic to champagne. Apparently it made him go bright red and hyperventilate. What’s odd about that is, there was a big empty box labeled Moët & Chandon in the kitchen when I checked it, the morning Chiswell died.”

“You never told me that.”

“We’d just found the body of a government minister. An empty box seemed relatively uninteresting at the time, and it never occurred to me it might be relevant to anything until I spoke to Izzy today.”

“Were there bottles inside?”

“Nothing, so far as I could see, and according to the family, Chiswell never entertained there. If he wasn’t drinking champagne himself, why was the box there?”

“You don’t think—”

“That’s exactly what I think,” said Strike. “I reckon that box was how the helium and the rubber tubing got into the house, disguised.”

“Wow,” said Robin, lying back on the unmade bed and looking up at the ceiling.

“Quite clever. The killer could’ve sent it to him as a gift, couldn’t they, knowing he was highly unlikely to open and drink it?”

“Bit slapdash,” said Robin. “What was to stop him opening it up anyway? Or re-gifting it?”

“We need to find out when it was sent,” Strike was saying. “Meanwhile, one minor mystery’s been cleared up. Freddie’s money clip was found.”

“Where?”

“Chiswell’s pocket. That was the flash of gold in the photograph you took.”

“Oh,” said Robin, blankly. “So he must have found it, before he died?”

“Well, it’d be hard for him to find it after he died.”

“Ha ha,” said Robin sarcastically. “There is another possibility.”

“That the killer planted it on the corpse? Funny you should say that. Izzy says she was very surprised when it turned up on the body, because if he’d found it, she would have assumed he’d have told her. He made a massive fuss about losing it, apparently.”

“He did,” Robin agreed. “I heard him on the phone, ranting on about it. They fingerprinted it, presumably?”

“Yeah. Nothing suspicious. Only his—but at this point, that means nothing. If there was a killer, it’s clear they wore gloves. I also asked Izzy about the bent sword, and we were right. It was Freddie’s old saber. Nobody knows how it got bent, but Chiswell’s fingerprints were the only ones on there. I suppose it’s possible Chiswell got it off the wall while drunk and sentimental and accidentally trod on it, but again, there’s nothing to say a gloved killer couldn’t have handled it as well.”

Robin sighed. Her elation at finding the note appeared to have been premature.

“So, still no real leads?”

“Hold your horses,” said Strike bracingly, “I’m leading up to the good stuff.

“Izzy managed to get a new phone number for that stable girl who can confirm Kinvara’s alibi, Tegan Butcher. I want you to give her a ring. I think you’ll seem less intimidating to her than I will.”

Robin jotted down the digits Strike read out.

“And after you’ve called Tegan, I want you to phone Raphael,” said Strike, giving her the second number he had got from Izzy. “I’d like to clear up once and for all what he was really up to, the morning his father died.”

“Will do,” said Robin, glad of something concrete to do.

“Barclay’s going to go back onto Jimmy and Flick,” said Strike, “and I…”

He left a small pause, deliberately dramatic, and Robin laughed.

“And you’re…”

“… am going to interview Billy Knight and Della Winn.”

“What?” said Robin, amazed. “How’re you going to get into the hosp—and she’ll never agree—”

“Well, that’s where you’re wrong,” said Strike. “Izzy dug Della’s number out of Chiswell’s records for me. I just rang her. I admit, I was expecting her to tell me to piss off—”

“—in slightly more elevated language, if I know Della,” Robin suggested.

“—and she sounded initially as though she wanted to,” admitted Strike, “but Aamir’s disappeared.”

“What?” said Robin, sharply.

“Calm down. ‘Disappeared’ is Della’s word. In reality, he resigned the day before yesterday and vacated his house, which hardly makes him a missing person. He’s not picking up the phone to her. She’s blaming me, because—her words again—I did ‘a fine job’ on him when I went round to question him. She says he’s very fragile and it’ll be my fault if he ends up doing himself a mischief. So—”

“You’ve offered to find him in exchange for her answering questions?”

“Right in one,” said Strike. “She jumped at the offer. Says I’ll be able to reassure him that he’s not in trouble and that nothing unsavory I might have heard about him will go any further.”

“I hope he’s all right,” said Robin, concerned. “He really didn’t like me, but that just proves he’s smarter than any of the rest of them. When are you meeting Della?”

“Seven o’clock this evening, at her house in Bermondsey. And tomorrow afternoon, if all goes to plan, I’m going to be talking to Billy. I checked with Barclay, and Jimmy’s got no plans to visit then, so I called the hospital. I’m waiting for Billy’s psychiatrist to call me back now and confirm.”

“You think they’ll let you question him?”

“Supervised, yeah, I think they will. They’re interested in seeing how lucid he is if he gets to talk to me. He’s back on his meds and greatly improved, but he’s still telling the story of the strangled kid. If the psychiatric team’s in agreement, I’m going to be visiting the locked ward tomorrow.”

“Well, great. It’s good to have things to be getting on with. God knows, we could use a breakthrough—even if it is about the death we’re not being paid to investigate,” she sighed.

“There might not be a death at the bottom of Billy’s story at all,” said Strike, “but it’s going to bug me forever unless we find out. I’ll let you know how I get on with Della.”

Robin wished him luck, bade him goodbye and ended the call, though she remained lying on her half-made bed. After a few seconds, she said aloud:

“Blanc de blancs.”

Once again, she had the sense of a buried memory shifting, issuing a gust of low mood. Where on earth had she seen that phrase, while feeling miserable?

“Blanc de blancs,” she repeated, getting off the bed. “Blanc d—ow!”

She had put her bare foot down on something small and very sharp. Bending down, she picked up a backless diamond stud earring.

At first, she merely stared at it, her pulse unaltered. The earring wasn’t hers. She owned no diamond studs. She wondered why she hadn’t trodden on it when she climbed into bed with a sleeping Matthew in the early hours of the morning. Perhaps her bare foot had missed it, or, more probably, the earring had been in the bed and displaced only when Robin pulled off the undersheet.

Of course, there were many diamond stud earrings in the world. The fact remained that the pair to which Robin’s attention had most recently been drawn had been Sarah Shadlock’s. Sarah had been wearing them the last time Robin and Matthew had gone to dinner, the night that Tom had attacked Matthew with sudden and apparently unwarranted ferocity.

For what felt like a very long time, but was in reality little over a minute, Robin sat contemplating the diamond in her hand. Then she laid the earring carefully on her bedside cabinet, picked up her mobile, entered “Settings,” removed her caller ID, then phoned Tom’s mobile.

He answered within a couple of rings, sounding grumpy. In the background, a presenter was wondering aloud what the forthcoming Olympic closing ceremony would be like.

“Yah, hello?”

Robin hung up. Tom wasn’t playing five-a-side football. She continued to sit, motionless, her phone in her hand, on the heavy matrimonial bed that had been so difficult to move up the narrow stairs of this lovely rented house, while her mind moved back over the clear signs that she, the detective, had willfully ignored.

“I’m so stupid,” Robin said quietly to the empty, sunlit room. “So bloody stupid.”