“Oh, no, no. She wasn’t the one who fucked up this case.” I took my hands away from my face. Richie was scarlet. “She swiped this envelope because she changed her mind about you, chum. And she’s not the only one. Once she spotted this, it struck her that you might not be the wonderful, trustworthy, stand-up guy she’d been picturing, which meant you might not in fact be the best person to take care of me. So she figured her only option was to do it herself, by bringing me the evidence that my partner had decided to run off with. Two for one: I get my case back, and I get to find out the truth about who I’m dealing with. Seems to me that, crazy or no, she was on to something.”

Richie, focusing on his shoes, said nothing. I asked, “Were you ever planning to tell me?”

That snapped him straight. “Yeah, I was. When I first found that yoke, I was, practically definitely. That’s why I bagged it and tagged it. If I hadn’t been planning on telling you, I could’ve just flushed it down the jacks.”

“Well, congratulations, old son. What do you want, a medal?” I nodded towards the evidence envelope. I couldn’t look at it; in the corner of my eye it seemed crammed tight with something alive and raging, a great insect thrumming against the thin paper and plastic, straining to split the seams and attack. “‘Collected in sitting-room, residence of Conor Brennan.’ While I was outside, on the phone to Larry. Is that right?”

Richie stared at the papers in his hand, blankly, like he couldn’t remember what they were. He opened his hand and let them scatter on the floor. “Yeah,” he said.

“Where was it?”

“Must’ve been on the carpet. I was putting back all that stuff that had been on the sofa, and this was hanging off the sleeve of a jumper. It wasn’t there when we took the clothes off the sofa—we gave them all a proper going-over, remember, in case any of them had blood on. The jumper must’ve picked it up off the floor.”

I asked, “What color jumper?” I already knew I would remember if Conor Brennan’s wardrobe had included rose-pink knitwear.

“Green. Khaki, like.”

And the carpet had been cream, with dirty green and yellow swirls. Larry’s lads could go over the flat with magnifying glasses, looking for a match to that wisp of pink, and find nothing. I had known, the moment I saw that fingernail, where the match was.

I asked, “And how did you interpret this find?”

There was a silence. Richie was looking at nothing. I said, “Detective Curran.”

He said, “The fingernail—the shape and the polish—it matches Jenny Spain’s. The wool that’s caught in it—” A corner of his mouth spasmed. “Looked to me like it matched the embroidery on the pillow that smothered Emma.”

The sodden thread that Cooper had fished out of her throat, while he held her frail jaw open between thumb and finger. “And what did you take that to mean?”