The PA squealed into life, ordered Dr. Something to Accident and Emergency please; Fiona didn’t move. Finally she nodded. Every muscle in her was still stretched taut, but that wariness had gone out of her face. “OK,” she said. “I’m on.”

“I need you to be sure.”

“I’m sure.”

“Then here’s what we’re going to do,” I said. The words felt heavy as stones, sinking me. “You’re going to mention to me that you’re heading out to Ocean View, to pick up supplies for your sister—her dressing gown, toiletries, her iPod, books, whatever you think she might need. I’m going to tell you that the house is still sealed and you can’t go in there. Instead, I’ll offer to drive out myself, go into the house and pick up whatever Jenny needs—I’ll bring you along, so that you can make sure I get the right things. You can make me a list on the way. Write it out, so I’ve got it to show anyone who asks.”

Fiona nodded. She was watching me like a floater at a briefing, alert and attentive, memorizing every word.

“Seeing the house again is going to jog your memory. All of a sudden you’ll remember that, on the morning when you and the uniformed officers found the bodies, when you followed the officers into the house, you picked up something that was lying at the bottom of the stairs. You did it automatically: the house was always so tidy that anything on the floor seemed out of place, so you tucked it in your coat pocket without even realizing what you were doing—your mind was on other things, after all. Does this all hang together for you?”

“The thing I picked up. What is it?”

“Jenny’s got a handful of bracelets in her jewelry box. Is there one she wears a lot? Not one of those solid things, what do you call them, bangles; we need a chain. A strong one.”

Fiona thought. “She’s got a charm bracelet. It’s a gold chain, a thick one; it looks pretty strong. Pat gave it to Jenny for her twenty-first, and after that he gave her charms when anything important happened—like a heart when they got married, and initials when the kids were born, and a little house when they bought the house. Jenny wears it a lot.”

“Perfect. That’s the other reason why you picked it up: you knew it meant a lot to Jenny, she wouldn’t want it lying around on the floor. When you saw what had happened, that blew the bracelet right out of your mind. Naturally enough, you haven’t thought of it since. But while you’re waiting for me to come out of the house, it’ll come back to you. You’ll go through your coat pockets and find it. When I get back to the car, you’ll hand it over to me, on the off chance that it might come in useful.”

Fiona said, “How’s that going to help?”

I said, “If everything had happened exactly the way I’m describing, then you wouldn’t have any way of knowing how the bracelet would fit into our investigation. So it’s better you don’t know it now. Less chance of you slipping up. You’re going to have to trust me.”