And, while it may sound like a stretch, for a time, that night with David in the library, I succeeded in finding what I had looked for that afternoon, that dark place on the other side of the ice. The great fall with no landing.

Peter was playing the piano. I could hear him from upstairs. A little jagged melody picked out with one hand, over and over, throbbing like a toothache.

There was a pot of coffee and some bacon sarnies on the side. I couldn’t see Em or Marcus, but the others were there. David didn’t look up as I came in.

“Morning, Andy,” Rob said. He looked cheerful, buoyant, like he’d won the pools. No one else was smiling.

“Where’s Em and Marcus?”

“Not sure. I suppose we should wait for them though, since it’s traditional.”

“Traditional for what? You’ve lost me, Rob,” I said.

“I mean the gathering of the suspects before the great detective—Poirot, Marple, in this case me—reveals the guilty party, or parties.”

“Someone steal the diamonds again?” They weren’t on the mantelpiece. I threw a quick glance at the rug in front of the fire.

“No, we’ve got a new mystery. I’m calling it the bodies in the library.”

With that, I knew what he was getting at and experienced a wave of horror, so like desire when you come to think of it, in the way it gripped you, made you feel like your organs were melting.

I poured out a coffee, the pot chattering against the rim of the cup. “Pete, where are Em and Marcus? We should get going.”

“Marcus went to look for her.” Peter was still picking out the little tune.

“Can you stop that? It’s driving me nuts.” His hands froze and then he set them down gently in his lap.

“Thing is, Andy,” Rob went on, “yours truly passed out last night on the couch in the library. Not that you’d have known that, because you went up so early. Dave too, when I think about it. Anyway, so there was I passed out on the couch and then about one, maybe two, I wake up. It’s pitch-black so I can’t see anything, but I’m hearing these noises. Can you guess what it was? No? Don’t want to take a guess, a wild stab in the dark?”

I heard the front door slam.

“Why don’t you shut your fucking mouth?”

“Rob, what are you talking about?” Alice had gotten to her feet.

For a moment, the impish mask slipped and Rob looked almost sad. “Sorry, sis,” he said. “But better you find out now than later. Better you know him for what he is.”

David still didn’t say anything. His eyes followed Rob. He didn’t even look particularly surprised.

Turning back to me, Rob went on. “It was a couple, Andy. Two people. Fucking. At it. Hammer and tongs. On my parents’ best Persian rug. Sixteen bedrooms to choose from—”