"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?"