‘I rang the doorbell,’ says Mary. ‘I was bloody amazed at my own nerve. Don’t ask me what I’d have said if someone had answered. I had no idea—it was an impulse thing. No one was in, though.’ She fumbles for another cigarette, lights it. ‘There’s a bay window to the right of the front door. Through it, I saw a framed photo of the happy couple, one of the ones you described in your letter: him kissing her cheek.’

Bile rises in my throat. That picture. Standing in Cherub Cottage’s pristine white sitting room, Stephen trying to kiss me . . .

‘I knew it was them. First Call had sent me press cuttings from the trial, photos, the works. I recognised their faces. Easy to see why you made it your mission in life to save him from captivity—that little-boy-lost look.’

‘They’re still together. He testified against her, she tried to pin the whole thing on him, and still they’re together, with those pictures on the walls.’ As if I never happened.

‘Tacky studio photos weren’t all they had up on the walls,’ says Mary with venom in her voice. ‘I saw something else go up.’

‘What do you mean?’ She made me write that letter, reliving everything I went through, when she knew. She already knew.

‘I waited, on the street. In my car. I’d gone as far as London—I wasn’t giving up that easily. After a while Simon Waterhouse came back.’

‘Did he see you?’

Mary shakes her head. ‘He was only interested in Crowther and Elton’s house. He had a snoop around, then went to sit in his car. Like me. At about half nine, Gemma Crowther and Aidan Seed walked up the road together.’

I try not to flinch.

‘Aidan opened the boot of his car, took something out, carried it into the house. I couldn’t see what it was—I wasn’t close enough, and there was a big white van parked behind Aidan’s car, blocking my view.’ Mary twists her hair round her hand. ‘The lights went on inside. Gemma closed the curtains. That’s when Waterhouse called it a night.’ Her smile is full of scorn for anyone who could give up so easily.

‘You didn’t?’ I guess.

‘No. There was a small gap in the curtains, but big enough to see through.’

Gemma Crowther and Aidan in a room together.

Mary waits for me to ask. When I don’t—can’t—she says, ‘There was a banging sound. He had a hammer in his hand. He was hanging a picture for her. Guess what picture?’

I freeze. It has to be, otherwise Mary would tell me. She wouldn’t make me guess. She blames me.

‘Yours,’ I say. ‘Abberton.’

‘My painting,’ says Mary, unemotional. ‘Yes. In the home of strangers. In the home of those strangers.’