Mom is in the grip of confession now, willing herself forward. “That’s why I agreed to do it. Your father loved her too much, but I could put myself in her place. I realized how lucky I’d been to have the life I’d had with you and Jenny, and I owed all that to Viola’s sacrifice. We all owed her, Penn.” My mother’s eyes shine with unshakable conviction. “Because she could have taken your father from us, if she’d wanted to.”

“Mom, you’re wrong.”

She forces a smile and nods, making a show of believing me, but the truth is in her eyes.

“So, it was you who botched the morphine at her antecubital vein?”

“Of course it was. Viola’s veins were in terrible shape, especially the big one at the elbow, which was the only one I had any chance of hitting. I pushed straight through the vessel. But I didn’t know that at the time. I have no medical experience. I left that house believing I had euthanized her.”

“Was that the only injection you gave her?”

“Yes.”

“And you drew the morphine out of the bottle yourself?”

“Yes.”

“How long after that did you leave the house?”

“As soon as Viola fell unconscious. I felt I should stay with her, but she’d told me I should leave. And once she was asleep, I felt so alone. Alone and afraid. I didn’t think there was any chance she would wake up.”

“And you never realized there was a tape in the camera?”

“God, no. I never even considered that.”

I blink in disbelief as the sequence of events comes clear in my mind. “So you couldn’t have killed her.”

My mother swallows audibly. “No. Sometimes I wake up wondering if the pharmacy somehow mislabeled the bottle, but Tom assured me they didn’t. The murder investigation would have uncovered that.”

“He’s right. Plus, if you’d injected that adrenaline, you would have known instantly. It would have hit Viola’s system before you got out of the room. She’d never have passed out. No, someone injected that adrenaline after you left.”

Relief fills her eyes, lessens some of the tightness in her face.

“The question is, who?”

“You don’t think it was Cora, do you?” she asks. “Or Lincoln? After all that business about the will? My God, it’s too horrible to think about.”

“I don’t think Cora could do that. Lincoln . . . I don’t know. I don’t think so.”

“I don’t believe he did it,” she says. “It had to be Snake Knox. And he’s still out there somewhere. That’s the hell of all this. The absurdity. Tom is in jail, and that monster is walking free, still killing people—”