“I can’t tell you that. When did you know?”

After a moment Fiona said, “When you told me Conor said he’d done it. I knew he hadn’t. No matter what had happened to him since I saw him, no matter if he had another fight with Pat and Jenny, even if he’d completely lost his mind: he wouldn’t do that.”

There was no doubt in her voice, not a thread. For a strange, exhausted moment I envied them both, her and Conor Brennan. Just about everything in this life is treacherous, ready to twist and shape-shift at any second; it seemed to me that the whole world would be a different place if you had someone you were certain of, certain to the bone, or if you could be that to someone else. I know husbands and wives who are that to each other. I know partners.

Fiona said, “At first I thought you were making it up, but I’m mostly pretty good at telling when people are lying. So I tried to think why Conor would say that. Probably he’d have done it to protect Pat, to keep him out of jail; but Pat was dead. That left Jenny.”

I heard the small, painful sound of her swallowing. “So,” she said, “I knew.”

“That’s why you didn’t tell Jenny that Conor had been arrested.”

“Yeah. I didn’t know what she’d do—if she’d try to own up, if she’d freak out and have a relapse or something …”

I said, “You were sure she was guilty, straightaway. You were positive Conor would never do this, but you didn’t feel the same way about your own sister.”

“You think I should have.”

“I don’t know what you should have thought,” I said. Rule Number Something: suspects and witnesses need to believe you’re omniscient; you never let them see you being anything other than sure. I couldn’t remember, any more, why it mattered. “I’m just wondering what made the difference.”

She twisted the scarf around her hand, trying to find the words. After a moment she said, “Jenny does everything right, and everything goes right for her. That’s how her life’s always worked. When something finally went wrong, when Pat was out of work … She didn’t know how to handle it. That’s why I was scared that she was going crazy, back when she said that about someone breaking in. I’d been worried ever since Pat lost his job. And I was right: she was going to pieces. Is that … ? Was that why she … ?”

I didn’t answer. Fiona said, low and fierce, pulling the scarf tighter, “I should have known. She did a good job of hiding it, after that, but if I’d been paying more attention, if I’d been out there more …”

There was nothing she could have done. I didn’t tell her that; I needed her guilt. Instead I said, “Have you brought this up with Jenny?”

“No. Jesus, no. Either she’d tell me to fuck off and never come back, or she’d tell me …” A flinch. “You think I want to hear her talk about it?”