"No," I said. "I just want to know about this girl. That's why I said I'd go to the meeting. It's got nothing to do with Frank and his wacko idea. I just want to hear about her."

"Why?" Sam demanded. He sat up and caught both my hands, making me look at him. There was a ragged edge to his voice, something frustrated and almost pleading. "What's she got to do with you? She's no relation to you, no friend of yours, nothing. She's happenstance, is all, Cassie: some girl who was looking for a new life and ran into the perfect chance."

"I know," I said. "I know, Sam. She doesn't even sound like a particularly nice person; if we'd met, I probably wouldn't have liked her. That's the whole point. I don't want her in my head. I don't want to be wondering about her. I'm hoping that if I find out enough about her, I can drop the whole thing and forget she ever existed."

"I've a double," Sam said. "He lives in Wexford, he's an engineer, and that's all I know about the man. About once a year, someone comes up to me and tells me I'm the spit of him--half the time they actually call me Brendan. We have a laugh about it, sometimes they take a photo of me on their phones to show him, and that's the end of that."

I shook my head. "That's different."

"How?"

"For one thing, he hasn't been murdered."

"No harm to the man," Sam said, "but I wouldn't give a damn if he were. Unless I caught the case, it'd be no problem of mine."

"This girl's my problem," I said. Sam's hands were big and warm and solid around mine, and his hair was falling across his forehead like it always does when he's worried. It was a spring Saturday night; we should have been walking on some beach down the country, surrounded by dark and waves and curlews, or making something experimental for dinner and playing music too loud, or settled in a corner of one of those rare out-of-the-way pubs where people still sing ballads when it gets past closing time. "I wish she wasn't, but she is."

"There's something here," Sam said, "that I'm not getting." He had let our hands drop onto my knees and was frowning down at them, running his thumb around one of my knuckles in a steady, automatic rhythm. "All I'm seeing is a bog-standard murder case, with a coincidence that could happen to anyone. Sure, I got a shock when I saw her, but that's only because I thought it was you. Once that was sorted, I figured everything would go back to normal. But you and Mackey, you're both acting like this girl was something to you; like it's personal. What am I missing?"

"In a way," I said, "it is personal, yeah. For Frank, partly it's exactly what you said--he thinks this would all be a big brilliant adventure. But it's more than that. Lexie Madison started out as his responsibility, she was his responsibility for eight months while I was under, she's his responsibility now."