And Fiona’s doubts hadn’t helped. I wondered whether Fiona had sensed, deep down, that she was nudging Jenny further off balance, or whether it had been innocent honesty; whether anything within families is ever innocent.

“So I just tried to ignore it all and keep going. I didn’t know what else to do. I cleaned the house even more; the second the kids got something messy, I’d tidy it away, or wash it—I was mopping the kitchen floor like three times a day. It wasn’t just to cheer Pat up any more. I needed to keep everything perfect, so that if anything was ever out of place, I’d know straightaway. I mean”—a flash of wariness—“it wasn’t a big deal, or anything. Like I told you before, I knew it was probably Pat moving stuff and forgetting. I was just making sure.”

And here I had thought she was shielding Conor. It had never even occurred to her that he was involved. She was positive that she had been hallucinating; all she could think about was the nightmare chance that the doctors would find out she was crazy and keep her here. What she was protecting was the most precious thing she had left: her plan.

“I understand,” I said. Under cover of shifting position, I checked my watch: we had been there around twenty minutes. Sooner or later, Fiona—especially if I was right about her—wouldn’t be able to make herself wait any longer. “And then … ? What changed?”

“Then,” Jenny said. The room was stifling and getting worse, but she had her arms wrapped around her body as if she was cold. “This one night, late, I went into the kitchen and Pat practically knocked the computer off the desk, trying to switch away from whatever he was doing. So I sat down next to him and I was like, ‘OK, you need to tell me what’s going on. I don’t care what it is, we can work through it, but I have to know.’ At first he was all, ‘Oh, everything’s fine, I’ve got it all under control, don’t worry about it.’ Of course that put me into a total panic—I was like, ‘Oh my God, what? What? Neither of us moves from this desk till you tell me what’s going on.’ And Pat, when he saw how scared I was, it just came pouring out of him: ‘I didn’t want to freak you out, I thought I could catch it and you’d never even have to know …’ And all this stuff about minks and polecats, and bones in the attic, and people online having ideas …”

That raw half-laugh again. “You know something? I was over the moon. I was like, ‘Wait, this is it? This is all that’s wrong?’ Here I’d been worrying about affairs and, I don’t know, terminal diseases, and Pat’s telling me we might have a rat or something. I practically burst into tears, I was so relieved. I went, ‘So we’ll ring an exterminator tomorrow. I don’t care if we have to get a bank loan, it’ll be worth it.’