“Come on, chickadee. I’m the wrong guy to mess with on this one. This is my job, planning this exact kind of stuff; I know when I see someone else doing it. Way back after you and me first talked about Rosie, you started thinking about that note you’d seen. So you asked me about her, nice and casually, and when you found out she’d been my girlfriend, you knew she had to be the one who’d written it. That’s when you started wondering why your uncle Shay would have a note from a dead girl stashed away in his drawer. Tell me if I’m going wrong here.”

No reaction. Boxing her in like a witness made me so tired I wanted to slide off my seat and go to sleep on the car floor. “So you worked on me till you got me to bring you over to your nana’s today. You left your maths homework till last, all weekend, so you could bring it along and use it to get your uncle Shay on his own. And then you went on at him till you got him talking about that note.”

Holly was biting down hard on the inside of her lip. I said, “I’m not giving out to you; you did a pretty impressive job of the whole thing. I’m just getting the facts straight.”

Shrug. “So what?”

“So here’s my question. If you didn’t think your uncle Shay had done anything wrong, then why did you go to all that hassle? Why not just tell me what you’d found, and let me talk to him about it?”

Down to her lap, almost too low to be intelligible: “Wasn’t any of your business.”

“But it was, honeybunch. And you knew it was. You knew Rosie was someone I cared about, you know I’m a detective, and you knew I was trying to find out what had happened to her. That makes that note very much my business. And it’s not like anyone had asked you to keep it a secret to begin with. So why didn’t you tell me, unless you knew there was something dodgy about it?”

Holly carefully unraveled a thread of red wool from her cardigan sleeve, stretched it between her fingers and examined it. For a second I thought she was going to answer, but instead she asked, “What was Rosie like?”