“What a mess,” I said. The dim, unfocused yellow light made the flat feel underground, suffocating. “What a five-star, twenty-four-carat, all-out mess.”

“Yeah,” Sam said, “well…” and hitched vaguely at the shoulders of his coat. He was looking past me, at the last stars fading in the window. “She was bad news from the beginning, that girl. It’ll all sort itself out in the end, I suppose. I’d better head. I’ve to be in early, have another go at those three, for all the good it’ll do. I just thought you should know.”

“Sam,” I said. I couldn’t stand up; it took all the guts I had left just to hold out my hand to him. “Stay.”

I saw him bite down on the inside of his lip. He still wouldn’t meet my eyes. “You should get some sleep too; you must be shattered. And I shouldn’t even be here, sure. IA said…”

I couldn’t say to him, When I was sure I was about to be shot, you were what I thought in my last second. I couldn’t even say Please. All I could do was sit there on the futon with my hand stretched out, not breathing, and hope to God that I hadn’t left it too late.

Sam ran a hand over his mouth. “I need to know something,” he said. “Are you transferring back to Undercover?”

“No,” I said. “Jesus, no. Not a chance in hell. This was different, Sam. This was a once-off.”

“Your man Mackey said-” Sam caught himself, shook his head in disgust. “That tosser,” he said.

“What did he say?”

“Ah, a load of old shite.” Sam sat down on the sofa with a thud, as if someone had cut his strings. “Once an undercover, always an undercover; you’d be back, now you’d had a taste of it. That kind of thing. I couldn’t… It was bad enough for a few weeks, Cassie. If you went back full-time… I can’t handle that. I can’t.”

I was too tired to get properly angry. “Frank was bullshitting,” I said. “It’s what he does best. He wouldn’t have me on his squad even if I wanted to be there-which I don’t. He just didn’t want you trying to get me to come home. He figured, if you thought I was where I belonged…”

“Sounds about right,” Sam said, “yeah.” He stared down at the coffee table, rubbed dust off it with his fingertips. “So you’re staying in DV? For definite?”

“If I’ve still got a job after yesterday, you mean?”

“Yesterday was Mackey’s fault,” Sam said, and even through all the exhaustion I saw the hard flare of anger across his face. “Not yours. Every single bloody bit of this is on Mackey. IA aren’t eejits; they’ll see that, same as everyone else does.”

“It wasn’t just Frank’s fault,” I said. “I was there, Sam. I let things get out of control, I let Daniel get his hands on a gun, and then I shot him. I can’t put that on Frank.”

“And I let him run with his lunatic bloody idea, and I’ve to live with that. But he’s the one who was in charge. When you take that on, you have to take responsibility for whatever comes out of it. If he tries to dump this mess on you-”

“He won’t,” I said. “Not his style.”

“Seems to me it’s exactly his style,” Sam said. He shook his head, shaking off the thought of Frank. “We’ll deal with that when it comes. But say you’re right, and he doesn’t shaft you to save his own arse; you’re staying in DV?”

“For now,” I said, “yeah. But down the line…” I hadn’t even known I was going to say this, it was the last thing I’d ever expected to come out of my mouth, but once I heard the words it seemed to me that they’d been waiting for me to find them ever since that luminous afternoon with Daniel, under the ivy. “I miss Murder, Sam. I miss it like hell, all the time. I want to come back.”

“Right,” Sam said. His head went back and he took a breath. “Yeah, I thought that, all right. That’s the end of us, then.”

You’re not allowed to go out with anyone on your squad-as O’Kelly elegantly puts it, no shagging on the company copier. “No,” I said. “Sam, no; it doesn’t have to be. Even if O’Kelly’s on for taking me back, there might not be an opening for years, and who knows where we’ll be by then? You could be running a squad of your own.” He didn’t smile. “If it comes down to it, we’ll just stay under the radar. It happens all the time, Sam. You know it does. Barry Norton and Elaine Leahy-” Norton and Leahy have been on Motor Vehicles for ten years and living together for eight of them. They pretend to carpool, and everyone including their super pretends not to know.

Sam shook his head, like a big dog waking up. “That’s not what I want,” he said. “All the best to them, and all, but I want this to be real. Maybe you’d be grand with having what they’ve got-I always figured that was one reason why you didn’t want to tell people about us, sure: so you could maybe come back to Murder, someday. But I’m not after a shag, or a fling, or some half-arsed part-time thing where we have to act like we’re…” He fumbled inside his coat; he was so exhausted that he was pawing at it as if he were drunk. “I’ve been carrying this around with me since two weeks after we started going out. Remember, we went for that walk round Howth Head? It was a Sunday?”

I remembered. A cool gray day, soft rain weightless in the air, wide smell of sea filling my chest; Sam’s mouth tasted of wild salt. We walked on the edges of high cliffs all afternoon and ate fish and chips on a bench for dinner, my legs were killing me, and it was the first time after Operation Vestal that I can remember feeling like me.

“The day after,” Sam said, “I bought this. On my lunch break.” He found what he’d been looking for and dropped it on the coffee table. It was a blue velvet ring box.

“Oh, Sam,” I said. “Oh, Sam.”

“I meant it,” Sam said. “This. You; us. I wasn’t just having a laugh.”

“Neither was I,” I said. That observation room; the look in his eyes. Was. “Never. I just… I got lost along the way, for a while. I’m so sorry, Sam. I fucked up every way there is, and I’m so sorry.”

“I love you, for Christ’s sake. You going off undercover like that, I nearly went mental-and I couldn’t even talk to anyone about it, because no one knew. I can’t…”

He trailed off, rubbed his eyes with the heels of his hands. I knew there had to be some delicate way of asking this, but the edges of my vision kept warping and flicking and I couldn’t think straight. I wondered if there could have been a worse time for this conversation. “Sam,” I said, “I killed a person today. Yesterday; whatever. I don’t have any brain cells left. You’re going to have to spell it out: are you breaking up with me or proposing to me?” I was pretty sure which one it was. All I wanted was to get it over with, do the good-bye routine, and chug the rest of the brandy till I knocked myself out.

Sam gave the ring box a baffled look, as if he wasn’t sure how it had got there. “Jesus,” he said. “I didn’t… I’d it all planned: dinner somewhere nice, with a view, like. And champagne. But I suppose-I mean, now that…”

He picked up the box, opened it. I couldn’t catch up; the only thing that registered was that he didn’t seem to be dumping me, and that the relief was purer and more painful than I could have imagined. Sam disentangled himself from the sofa and got down on one knee, clumsily, on the floor.

“Right,” he said, and held out the box to me. He was white and wide-eyed; he looked as stunned as I was. “Will you marry me?”

The only thing I wanted to do was laugh-not at him, just at the sheer screaming pitch of crazy that day had managed to hit. I was scared that if I started I wouldn’t be able to stop. “I know,” Sam said, and swallowed, “I know it’d mean you couldn’t come back to Murder-not without special permission, and…”

“And neither of us is going to get any special treatment any time soon,” I said. Daniel’s voice brushed along my cheek like dark feathers, like a long night wind coming down from some far mountain. Take what you want and pay for it, says God.

“Yeah. If… God. If you want to think about it…” Another swallow. “You don’t need to decide right now, sure. I know tonight’s not the best moment for… But maybe it needed doing. Sooner or later, I need to know.”