I grab a chair from the kitchen and sit opposite her. She closes her eyes and lets the tea warm her hands and face. I give her as long as I can bear before asking, “Cara, can you tell me what happened?”

“We need to stop, Jon.” Her dry lips quiver around her words. “We have to stop all of it, it’s too dangerous, we don’t know what we’re getting into. We just need to stop.” She keeps her eyes fixed on her tea. “I met GoodSam,” she says quietly, addressing the mug in her hands.

“You did what?” I wasn’t expecting this.

“I saw Grace, Jon, I saw Grace and I couldn’t just do nothing, pretend I hadn’t seen her. I had to do something.”

How fucking stupid of me. I should have guessed she would do something like this. If I’m honest, I’d probably have done the same if it had occurred to me to contact GoodSam, but I’m still livid with her for putting herself at risk.

“So you met up with a possible lead, someone we know nothing about, on your own and without even telling me? He could be a fucking kidnapper for all we know, Cara!” Simon has been transferred to a secure psychiatric unit, and Upton and others are trying to press him for information as much as they can. I still think Simon knows more than he’s admitting but, having met him, my instinct is he’s telling the truth—he doesn’t know where Grace is, and I remember how clear his voice was: “I could never hurt Meg.” That means the killer is still out there, it means GoodSam could know where Grace is, he could be dangerous, and I’m livid with Cara for being so stupid.

“That’s just it. I don’t think he kidnapped her. I don’t think anyone did.”

I stare at Cara. Her face is pinched. She looks like I feel. Is she, like me, starting to question the authenticity of Grace’s illnesses? If I’m right and Grace wasn’t as sick as we thought, then it is possible Grace could walk, or even run. It is possible that Cara saw her in the graveyard.

At last Cara pulls her eyes away from mine. She lowers her head and starts sobbing into her chest.

“Oh shit, Cara,” I say clumsily. I sit down on the sofa next to her. “God, I’m sorry, I’m sorry I didn’t believe you.”

Cara starts shaking her head to show that’s not why she’s crying. “We have to stop now. This, this person I met, he said stuff about my mum, about what he would do if we didn’t stop . . .” Her voice trails away. She looks up at me and I see the fear, bright and alive behind her eyes. “And he said if we went to the police he’d hurt Mum. So we just . . . we just have to stop everything, OK?”

Her eyes seek reassurance. I look away, because I know I’m going to have to lie.