“He doesn’t know we’ve recovered anything off the computer. Doesn’t want us knowing Pat was losing the plot, in case we cop on that he’s covering for Pat.”

“If he is. If. ” I had known Richie wasn’t on side yet, but hearing it out loud set me pacing tight circles in the corridor. Every muscle in me was twitching from making myself sit still at that table for so long. “Has it occurred to you how else he could have known?”

Richie said, “Him and Jenny were having an affair. Jenny told him about the animal.”

“Yes. Maybe. Could be. We’ll find out. But that’s not what I’ve got in mind. Losing the plot, you said: Pat was losing the plot. What if that was what Pat was supposed to think, too?”

Richie shoved himself back against the wall and tucked his hands in his pockets. He said, “Go on.”

I said, “Remember what that hunter guy on the internet said, the one who recommended the trap? He wanted to know if there was any chance Pat’s kids were messing about with it. Now, we know the kids were too little for that, but there’s someone else who wasn’t. Someone who had access.”

“You think Conor let the animal out of the trap? Took the bait mouse away?”

I couldn’t stop circling. I wished we had an observation room, somewhere I could move fast and not have to keep my voice down. “Maybe that. Maybe even more than that. Fact: to begin with, at least, Conor was fucking with Jenny’s head. Eating her food, nicking her bits and pieces—he can keep telling us till the cows come home that he didn’t want to scare her, but the fact is, that’s what he did: freaked the shit out of her. He had Fiona thinking Jenny was losing her mind; probably he had Jenny thinking the same thing. What if he did the same to Pat?”

“How, like?”

“Whatshisname, Dr. Dolittle, he said he couldn’t swear there had ever been an animal in that attic. You took that to mean that Pat Spain was imagining the whole thing. What if there never was an animal because it was all Conor’s doing?”

That sent something vivid shooting across Richie’s face: skepticism, defensiveness, I couldn’t tell what. I said, “Every sign Pat talked about, everything we’ve seen, could have been faked by anyone who had access to that house. You heard Dr. Dolittle, what he said about that robin: an animal’s teeth could have taken its head off, but so could a knife. Those gouges on the attic beam: could be claw marks, could be blade marks or nail marks. The skeletons: an animal isn’t the only thing that can strip a couple of squirrels to bones.”

“The noises?”

“Oh, yeah. Let’s not forget the noises. Remember what Pat posted, way back on the Wildwatcher board? There’s a space about eight inches deep between the attic floor and the ceiling below. How hard would it be to get a remote-controlled MP3 player and a good set of speakers, plant them in that space, and switch on a track of scratching and banging every time you see Pat going upstairs? Hide them behind bits of insulation, so that if he goes looking around the space with a torch—like he did—he’ll see nothing. It’s not like he’ll be looking for an electronic gadget, anyway; he’ll be looking for hairs, droppings, an animal, and no fear of him spotting any of those. If you want a little extra fun, then you switch off the track whenever Jenny’s around, so she starts to wonder if Pat’s going off his trolley. Swap the batteries every time you break in—or just find a way to run the system off the house electricity—and your little game can keep going for as long as it takes.”