“Which would’ve needed doing anyway. Quit guilt-tripping me.”

“-and if you’re absolutely positive, then there’s no point in you wasting any more of your time and mine by humoring me.”

“You wanted me to humor you,” I pointed out. “Just for three days, no commitment, blah blah blah.”

He nodded, thoughtfully. “And that’s all you’ve been doing here: humoring me. You’re happy in DV. You’re sure.”

The truth is that Frank had-it’s a talent-hit a nerve. Maybe it was seeing him again, his grin and the fast rhythms of his voice snapping me straight back to when this job looked so shiny and fine I just wanted to take a running leap and dive in. Maybe it was the fizz of spring in the air, tugging at me; maybe it was just that I’ve never been any good at staying miserable for any length of time. But whatever the reason, I felt like I was awake for the first time in months, and suddenly the thought of going into DV on Monday-though I had no intention of telling Frank this-made me itch all over. I was working with this Kerryman called Maher who wore golf sweaters and thought any non-Irish accent was a source of endless amusement and breathed through his mouth when he typed, and all of a sudden I wasn’t sure I could make it through another hour of his company without throwing my stapler at his head.

“What’s that got to do with this case?” I asked.

Frank shrugged, stubbed out his cigarette. “Just curious. The Cassie Maddox I knew wouldn’t have been happy on some nice safe nine-to-five she could do in her sleep. That’s all.”

Suddenly and fiercely, I wanted Frank out of my flat. He made it feel too small, crowded and dangerous. “Yeah, well,” I said, picking up the wineglasses and taking them over to the sink. “Long time no see.”

“Cassie,” Frank said behind me, in his gentlest voice. “What happened to you?”

“I found Jesus Christ as my Personal Savior,” I said, slamming the glasses into the sink, “and he doesn’t approve of fucking with people’s heads. I got a brain transplant, I got mad cow disease, I got stabbed and I got older and I got sense, you can call it whatever you like, I don’t know what happened, Frank. All I know is I want some bloody peace and quiet in my life for a change, and this fucked-up case and this fucked-up idea of yours are unlikely to give me it. OK?”

“Hey, fair enough,” Frank said, in an equable voice that made me feel like an idiot. “It’s your call. But if I promise not to go on about the case, can I get another glass of wine?”

My hands were shaking. I turned on the tap hard and didn’t answer.

“We can catch up. Like you said, long time no see. We’ll bitch about the weather, I’ll show you photos of my kid and you can tell me all about your new fella. What happened to Whatsisname who you were seeing before, the barrister? I always thought he was a little square for you.”

Undercover happened to Aidan. He dumped me when I kept breaking appointments, wouldn’t tell him why and wouldn’t tell him what I did all day. He said I cared more about the job than about him. I rinsed out the glasses and shoved them onto the draining rack.

“Unless you need time on your own, to think this over,” Frank added, solicitously. “I can understand that. It’s a big decision.”

I couldn’t help it: after a second, I laughed. Frank can be a little bollocks when he feels like it. If I threw him out now, it would be as good as saying I was considering his wacko idea. “OK,” I said. “Fine. Have all the wine you want. But if you mention this case once more, I’m going to give you a dead arm. Fair enough?”

“Beautiful,” Frank said happily. “Usually I have to pay for that kind of thing.”

“For you, I’ll do freebies any time.” I threw the glasses back to him, one by one. He dried them on his shirt and reached for the wine bottle.

“So,” he said. “What’s our Sammy like in the scratcher?”

We finished off the first bottle and got started on the second. Frank gave me the Undercover gossip, the stuff that other squads never hear. I knew exactly what he was doing, but it still felt good, hearing the names again, the jargon, the dangerous in-jokes and the fast, truncated professional rhythms. We played do-you-remember: the time I was at a party and Frank needed to get me some piece of info, so he sent another agent to play the rejected suitor and do a Stanley Kowalski under the window (“Lexiiiiiie!”) until I came out; the time we were having an update session on a bench in Merrion Square and I saw someone from college heading our way, so I called Frank an old pervert at the top of my lungs and flounced off. I realized that, whether I wanted to or not, I was enjoying having Frank there. I used to have people over all the time-friends, my old partner, sprawled on the sofa and staying up too late, music in the background and everyone a little tipsy-but it had been a long time since anyone but Sam had been to my flat, a longer time since I had laughed like this, and it felt good.

“You know,” Frank said meditatively, a lot later, squinting into his glass, “you still haven’t said no.”

I didn’t have the energy to get annoyed. “Have I said anything that sounds remotely like a yes?” I inquired.

He snapped his fingers. “Here, I’ve got an idea. There’s a case meeting tomorrow evening. Why don’t you come along? That might help you decide whether you want in.”

And bingo, there it was: the hook in the middle of the lures, the real agenda behind all the chocolate biscuits and updates and concern for my emotional health. “Jesus, Frank,” I said. “Do you realize how obvious you are?”

Frank grinned, not the least bit shamefaced. “You can’t blame a guy for trying. Seriously, you should come. The floaters don’t start till Monday morning, so it’ll basically be just me and Sam, having a chat about what we’ve got. Aren’t you curious?”

Of course I was. All Frank’s info hadn’t told me the one thing I wanted to know: what this girl had been like. I leaned my head back on the futon and lit another smoke. “Do you seriously think we could pull this off?” I asked.

Frank considered this. He poured himself another glass of wine and waved the bottle at me; I shook my head. “Under normal circumstances,” he said at last, settling back into the sofa, “I’d say probably not. But these aren’t normal circumstances, and we’ve got a couple of things in our favor, besides the obvious. For one thing, to all intents and purposes, this girl only existed for three years. It’s not like you’d have to deal with a lifetime’s worth of history here. You don’t have to get by parents or siblings, you’re not going to run into some childhood friend, nobody’s going to ask you if you remember your first school dance. For another thing, during those three years, her life seems to have been pretty tightly circumscribed: she ran with one small crowd, studied in one small department, held down one job. You don’t need to get the hang of wide circles of family and friends and colleagues.”

“She was doing a PhD in English literature,” I pointed out. “I know zip about English literature, Frank. I got an A in my Leaving Cert, but that’s it. I don’t speak the jargon.”

Frank shrugged. “Neither did Lexie, as far as we know, and she managed to pull it off. If she can do it, so can you. Again, we’re in luck there: she could’ve been doing pharmacy, or engineering. And if you get sweet fuck-all done on her thesis, well, hey, what do they expect? Ironically enough, that stab wound’s going to come in useful: we can give you post-traumatic stress, amnesia, whatever we fancy.”

“Any boyfriend?” There is a limit to what I’m prepared to do for the job.

“No, so your virtue is safe. And the other thing working for us: you know those photos? Our girl had a video phone, and it looks like the five of them used it as the group camcorder. The image quality’s not brilliant, but she had a whacking great memory card and it’s packed with clips-her and her mates on nights out, on picnics, moving into their new gaff, doing it up, everything. So you’ve got a ready-made guide to her voice, her body language, mannerisms, the tone of the relationships-everything a girl could ask for. And you’re good, Cassie. You’re a damn fine undercover. Put it all together, and I’d say we’re in with a pretty good chance of pulling this off.”