St. James said to Lynley, “Yes, as you see,” in answer to his ah. He employed an even tone in which something about the state of the room was communicated between them.

Beyond this workplace, a second door opened into what was apparently a darkroom, and it was from this space that liquid pooled out. Fixer, Deborah St. James explained as she finished mopping it up. She’d spilled an entire gallon of the stuff. “One never spills when a container is nearly empty, have you noticed?” she asked. Job done, she stood and shook back her hair. She reached in the pocket of the bib overalls she was wearing-these were olive linen, wrinkled, and they suited her in ways that would have seemed ridiculous on another woman-and she brought out an enormous hair slide. She was the kind of woman who could gather up her hair in a single deft movement and make it look fashionably disheveled. She wasn’t at all beautiful, Isabelle thought, but she was natural and that was her appeal.

That she appealed to Lynley was something he didn’t hide. He said, “Deb,” and hugged her, kissing her on the cheek. Briefly, Deborah’s fingers touched the back of his neck. “Tommy,” she said in reply.

St. James watched this, his face perfectly unreadable. Then he removed his gaze from his wife and Lynley to Isabelle and said lightly, “How’re you getting on with the Met, then? You’ve been thrown in feetfirst, I dare say.”

“I suppose that’s better than headfirst,” Isabelle replied.

Deborah said, “Dad’s doing us drinks. Did he offer you…? Well, of course he did. Let’s not have them up here. There’s got to be air in the garden. Unless…” She looked from Lynley to Isabelle. “Is this business, Tommy?”

“It can be done in the garden as easily as here.”

“With me? With Simon?”

“Simon this time,” and to St. James, “if you’ve a moment. It shouldn’t take long.”

“I was finished here anyway.” St. James looked round the room and added, “She had the maddest system of organising things, Tommy. I swear to you, I still can’t work it out.”

“She meant to be indispensable to you.”

“Well, she was that.”

Isabelle looked between them once again. Some sort of code, she reckoned.

Deborah said, “It’ll come right eventually, don’t you think?” but it seemed that she wasn’t speaking of the files. Then she smiled at Isabelle and said, “Let’s get out of here.”

The little dog had settled on a tattered blanket in one corner of the room, but she heroically scuttled back down the stairs she’d just come up when she realised their intentions. At the ground floor, Deborah called, “Dad, we’re going to the garden,” and Joseph Cotter replied, “Be there in a tic, then,” from the study where the sound of glass clinking against metal suggested that drinks were being placed on a tray.

The garden comprised lawn, brick patio, herbaceous borders, and an ornamental cherry tree. Deborah St. James led Isabelle to a table and chairs beneath this, chatting about the weather. When they’d sat, she changed gears, directing a long look at Isabelle. “How’s he getting on?” she asked frankly. “We worry about him.”

Isabelle said, “I’m not the best judge, as I’ve not worked with him before. He seems to be doing perfectly well as far as I can tell. He’s very kind, isn’t he?”

Deborah didn’t reply at first. She gazed at the house as if seeing the men within it. After a moment she said, “Helen worked with Simon. Tommy’s wife.”

“Did she? I’d no idea. She was a forensic specialist?”

“No, no. She was…Well, she was rather uniquely Helen. She helped him when he needed her, which usually worked out to be three or four times each week. He misses her terribly, but he won’t talk about it.” She removed her gaze from the house back to Isabelle. “Years ago, they intended to marry-Simon and Helen-but they never did. Well, obviously, they didn’t,” she added with a smile, “and Helen eventually married Tommy. Bit of a difficult situation, isn’t it, making the change from lovers to friends.”

Isabelle didn’t ask why Lynley’s wife and Deborah’s husband had not married. She wanted to do so, but the arrival of the two men supervened, and on their heels came Joseph Cotter with the tray of drinks and the household dog who bounded across the lawn with a yellow ball in her mouth that she proceeded to chew on, plopping herself at Deborah’s feet.

More conversation about the weather followed, but soon enough, Lynley brought up the ostensible reason for this visit to Chelsea. He handed to Simon the manila envelope he’d been carrying in Isabelle’s office. Simon opened it and drew out its contents. Isabelle saw it was the photograph of the yellow shirt from the Oxfam bin.

“What d’you make of it?” Lynley asked his friend.

St. James studied it for a minute in silence before he said, “I should think it’s arterial blood. The pattern on the front of the shirt? It’s a spray.”

“Suggesting?”

“Suggesting this was worn by the killer, and he stood quite close to the victim when he struck the fatal blow. Look at the spray on the collar of the shirt.”

“What d’you reckon that means?”

St. James thought about this, his expression distant. He responded with, “Oddly enough…? I’d say in the midst of an embrace. Anything else and the heaviest spray would surely be on the sleeve, not on the collar and the front of the shirt. Let me show you. Deborah?”

He rose from his chair, no easy business for him because he was disabled. Isabelle hadn’t noticed this earlier. He wore a leg brace, which made his movements awkward.

His wife rose as well and stood as directed by her husband. He put his left arm round her waist and drew her to him. He bent as if to kiss her, and as he did so, he lifted his right hand and brought it down on her neck. The demonstration completed, he touched his wife lightly on the hair and said to Lynley with an indication of the photo, “You can see the heaviest part of the spray is high on the right breast of the shirt. He’s taller than she was, but not by much.”

“Not a defensive wound on her, Simon.”

“Suggesting she knew him well.”

“She was there with him willingly?”

“I dare say.”

Isabelle said nothing. She saw the purpose of this call upon the St. Jameses, and she didn’t know whether to be grateful that Lynley hadn’t made these points-which she reckoned he’d already deduced from the photo-during the team’s meeting at the Met or angry that he had decided to do it this way, in the presence of his friends. She was hardly likely to argue with him here, and he must have known that. It was yet another nail in the coffin of Matsumoto as killer. She had to regroup and she had to do it in haste.

She stirred in her seat. She nodded sagely and made noises about being grateful for their time and, unfortunately, having to be on her way. There were various things to see to, an early morning, the expectation of a witness to be interviewed, undoubtedly a meeting with Hillier…? They would understand, of course.

Deborah was the one to see her to the door. Isabelle thought to ask her if, on the day of the photo, she remembered anything, anyone, any circumstance remotely unusual?

Deborah said the expected. It had been more than six months ago. She could remember virtually nothing about it other than Sidney-“Simon’s sister”-St. James being present. “Oh, and there would be Matt as well,” Deborah added. “He was there.”

“Matt?”

“Matt Jones. Sidney’s partner. He brought her to the cemetery and watched for a few minutes. But he didn’t stay. Sorry. I should have mentioned it earlier. I hadn’t really considered him till now.”

Isabelle was thinking about this as she began to trace the route back to her car. But she hadn’t got far in her speculation when she heard her name called. She turned to see Lynley coming towards her down the pavement. She said when he reached her, “Matt Jones.”

He said, “Who?” He had the manila envelope in his possession again. She gestured for it. He handed it over.