“Sam,” I said. “Is there any way you could hold off on putting her picture out for a day or two? Just till I can warn people.” I had no idea how I was going to word this one. See, Aunt Louisa, we found this dead girl and…

“Interestingly,” Frank said, “now that you mention it, that fits right in with my little idea.” There was a jumble of moss-covered boulders piled in the corner of the field; he pulled himself backwards onto them and sat there, one leg swinging.

I’d seen that gleam in his eyes before. It always meant he was about to come out, spectacularly casually, with something totally outrageous. “What, Frank,” I said.

“Well,” Frank began, getting comfortable against the rocks and folding his arms behind his head, “we’ve got a unique opportunity here, haven’t we? Shame to waste it.”

“We do?” Sam said.

“We do?” I said.

“Oh, yeah. Jesus, yeah.” That risky grin was starting at the corners of Frank’s mouth. “We’ve got the chance,” he said, taking his time, “we’ve got the chance to investigate a murder case from the inside. We’ve got the chance to place an experienced undercover officer smack in the middle of a murder victim’s life.”

We both stared at him.

“When have you ever seen anything like that before? It’s beautiful, Cass. It’s a work of art.”

“Work of arse, more like,” I said. “What the hell are you on about, Frankie?”

Frank spread his arms like it was obvious. “Look. You’ve been Lexie Madison before, right? You can be her again. You can-no, hang on, hear me out-if she’s not dead, just wounded, right? You can walk straight back into her life and pick up where she left off.”

“Oh my God,” I said. “This is why no Bureau and no morgue guys? This is why you made me dress like a dork? So nobody notices you have a spare?” I pulled my hat off and stuffed it back in my bag. Even for Frank, this had taken some fast thinking. Within seconds of arriving at the scene, he must have had this in his head.

“You can get hold of info no cop would ever learn, you can get close to everyone she was close to, you can identify suspects-”

“You want to use her as bait,” Sam said, too levelly.

“I want to use her as a detective, mate,” Frank said. “Which is what she is, last time I checked.”

“You want to put her in there so this fella will come back to finish the job. That’s bait.”

“So? Undercovers are bait all the time. I’m not asking her to do anything I wouldn’t do myself in a heartbeat, if-”

“No,” Sam said. “No way.”

Frank raised an eyebrow. “What are you, her ma?”

“I’m the lead investigator on this case, and I’m saying no way.”

“You might want to think about it for more than ten seconds, pal, before you-”

I might as well not have been there. “Hello?” I said.

They turned and stared at me. “Sorry,” Sam said, somewhere between sheepish and defiant.

“Hi,” Frank said, grinning at me.

“Frank,” I said, “this is officially the looniest idea I’ve ever heard in my life. You are off your bloody trolley. You are up the wall and tickling the bricks. You are-”

“What’s loony about it?” Frank demanded, injured.

“Jesus,” I said. I ran my hands through my hair and turned full circle, trying to figure out where to start. Hills, fields, spaced-out uniforms, cottage with dead girl: this wasn’t some messed-up dream. “OK, just for starters, it’s impossible. I’ve never even heard of anything like this before.”

“But that’s the beauty of it,” Frank explained.

“If you go under as someone who actually exists, it’s for like half an hour, Frank, and it’s to do something specific. It’s to do a drop-off or a pickup or something, from a stranger. You’re talking about me jumping right into the middle of this girl’s life, just because I look a bit like her-”

"A bit?”

“Do you even know what color her eyes are? What if they’re blue, or-”

“Give me some credit, babe. They’re brown.”

“Or what if she programs computers, or plays tennis? What if she’s left-handed? It can’t be done. I’d be burned inside an hour.”

Frank pulled a squashed pack of smokes out of his jacket pocket and fished out a cigarette. He had that glint in his eye again; he loves a challenge. “I have every faith in you. Want a smoke?”

“No,” I said, even though I did. I couldn’t stop moving, up and down and around the patch of long grass between us. I don’t even like her, I wanted to say, which made no sense at all.

Frank shrugged and lit up. “Let me worry about whether it’s possible. It might not be, I’ll grant you that, but I’ll figure that out as we go along. What’s next?”

Sam was looking away, his hands shoved deep in his pockets, leaving me to it. “Next,” I said, “it’s somewhere out on the other side of unethical. This girl must have family, friends. You’re going to tell them she’s alive and well and just needs a few stitches, while she’s lying on a table in the morgue with Cooper slicing her open? Jesus, Frank.”

“She’s living under a fake name, Cass,” Frank said, reasonably. “You really think she’s in touch with her family? By the time we track them down, this will all be over. They’ll never know the difference.”

“So what about her mates? The uniforms said she lives with a bunch of others. What if she’s got a boyfriend?”

“The people who care about her,” Frank said, “will want us to catch the guy who did this to her. Whatever it takes. That’s what I’d want.” He blew smoke up at the sky.

Sam’s shoulders shifted. He thought Frank was just being smart-arsed. But Sam’s never done undercover, he had no way of knowing: undercovers are different. There is nothing they won’t do, to themselves or anyone else, to take their guy down. There was no point in arguing with Frank on this one, because he meant what he had said: if his kid were killed, and someone kept that from him in order to get the guy, he would take it without a murmur. It’s one of the most powerful lures of undercover, the ruthlessness, no borderlines; strong stuff, strong enough to take your breath away. It’s one of the reasons I left.

“And then what?” I said. “When it’s over. You tell them, ‘Oops, by the way, we forgot to mention, that’s a ringer; your mate died three weeks ago?’ Or do I keep being Lexie Madison till I can die of old age?”

Frank squinted into the sun, considering this. “Your wound can get infected,” he said, brightening. “You’ll go into the ICU and the doctors will try everything modern medicine can offer, but no go.”

“Jesus Christ on a bike,” I said. I felt like this was all I had said, all morning long. “What on earth is making this seem like a good idea to you?”

“What’s next?” Frank asked. “Come on, hit me.”

“Next,” Sam said, still looking away down the lane, “it’s bloody dangerous.”

Frank raised one eyebrow and tilted his head at Sam, giving me a wicked private grin. For an off-balance second I had to stop myself grinning back.

“Next,” I said, “it’s too late anyway. Byrne and Doherty and Whatsisname with the dog all know there’s a dead woman in there. You’re telling me you can get all three of them to keep their mouths shut, just because it suits you? Whatsisname’s probably told half of Wicklow already.”

“Whatsisname is Richard Doyle, and I’m not planning on getting him to keep his mouth shut. As soon as we’re done here, I’m going to go congratulate him on saving this young woman’s life. If he hadn’t shown great presence of mind by calling us immediately, the outcome could have been tragic. He’s a hero, and he can tell as many people as he likes. And you saw Byrne, babe. That’s not a happy little member of our glorious brotherhood. If I hint that there might be a transfer in it for him, not only will he keep his mouth shut, he’ll keep Doherty’s shut too. Next?”

“Next,” I said, “it’s pointless. Sam’s worked dozens of murders, Frank, and he’s solved most of them, without needing to pull any wack-job stunts. This thing you’re talking about would take weeks to set up-”