“It hangs together, near enough. It hangs.” I slid Jenny’s underwear drawer shut. “Except for one thing: why?”

“You mean why would your man be after the Spains, like?”

“Why would he do any of it? We’re talking about months of stalking, topped off with mass murder. Why pick this family? Why break in and do nothing worse than eat ham slices? Why break in again and bash the walls in? Why escalate to murder? Why take the risk of starting with the kids? Why suffocate them but stab the adults? Why any of it?”

Richie fished fifty cents out of the back pocket of the khakis and shrugged—he did it like a kid, shoulders jumping around his ears. “Maybe he’s mental.”

I stopped what I was doing. “Is that what you’re planning on putting in the file for the Director of Public Prosecutions? ‘I dunno, maybe he’s, like, totally mental’?”

Richie flushed, but he didn’t back down. “I don’t know what the doctors’d call it. But you know what I mean.”

“Actually, old son, I don’t. ‘Mental’ isn’t a reason. It comes in an awful lot of flavors, most of them are non-violent, and every single one of them has some kind of logic, whether or not it makes sense to you and me. Nobody slaughters a family because, hey, I just felt mental today.”

“You asked for a theory that covers what we’ve got. That’s the best I can come up with.”

“A theory that’s built on ‘because he’s mental’ isn’t a theory. It’s a cheap cop-out. And it’s lazy thinking. I expect better from you, Detective.”

I turned my shoulder to him and went back to the drawers, but I could feel him behind me, not moving. I said, “Spit it out.”

“What I told your woman Gogan. That she didn’t need to worry about some psycho. I just wanted to stop her ringing around the talk shows, but fact is, she’s got a right to be scared. I don’t know what word you want me to use, but if this fella’s mental, then nobody has to go asking for trouble. He’s bringing it with him.”

I slid the drawer shut, leaned back against the chest and stuck my hands in my pockets. “There was a philosopher,” I said, “a few hundred years back, who said you should always go for the simplest solution. And he wasn’t talking about the easy answer. He meant the solution that involves throwing in the fewest extras on top of what you’ve actually got on hand. The fewest ifs and maybes, the fewest unknown guys who might possibly have just happened to wander up in the middle of the action. Do you see where I’m going with this?”

Richie said, “You don’t think there was any intruder.”

“Wrong. I think that what we’ve got on hand is Patrick and Jennifer Spain, and any solution that involves them needs fewer extras than a solution that doesn’t. What happened here came from one of two places: inside this house, or outside. I’m not saying there was no intruder. I’m saying that even if the killer came from outside, the simplest solution is that the reason came from inside.”