Charlie shakes her head. ‘Sam and Aidan are with him. I haven’t seen him. No, I asked one of the wardens if I could see a list of Smith’s visitors. There was a Martha Heathcote on the list. Heathcote was her house at Villiers. I checked. The warden I asked was very helpful. He remembered Smith being extremely distressed after the visit. It’s the only visit he’s had since he’s been here—everyone thought he’d be delighted but he wasn’t. The opposite. Ms Heathcote brought him two presents, both of which he wanted nothing to do with. He told the prison staff to burn them. One was this picture. The other was a book.’

‘Ice on the Sun,’ I murmur.

‘Yes. Which is now in the prison library,’ says Charlie. ‘Resources are finite, here like everywhere else. They weren’t about to throw away a book that could go in the prison library or a painting they could stick on the wall.’

‘It’s not signed,’ I say, staring at the picture. Aidan has described it to me, but seeing it—or rather, seeing Martha’s replica—is something altogether different. The painting is of a bedroom at night. The room’s dark, but some light’s coming in through the curtains. It looks as if it might be the early hours of the morning. There are three people in the bed: an older man, asleep, wearing a sweat-stained vest, turned on his side, a yellowing pillow beneath his head, a dribble stain by his mouth. Then there’s a naked woman in the middle of the bed. Her eyes are wide open and there are faint bruises on her neck. I’m not sure anyone would say with certainty that she was dead unless they knew. On her other side, there’s a young man, or an old boy, wearing a T-shirt and a pair of shorts, sitting up, hugging his knees and crying, looking at the person looking at the picture. Aidan. She’s captured him perfectly: how he must have looked, how he must have felt.

‘He needs to see this,’ I say. ‘Can he use it to prove what happened if . . . if his stepfather won’t . . .’

Charlie’s shaking her head. ‘He won’t need to, though. Smith will do what Aidan wants him to do. It’ll be okay, you’ll see.’

‘It will,’ Saul echoes, squeezing my arm.

‘Even if she’d put the right title on it . . .’ says Charlie.

‘What do you mean, the right title?’ I look carefully, but can’t see a title anywhere. There’s no writing at all on the picture.

‘I thought she’d have called it The Murder of Mary Trelease,’ says Charlie. ‘I can’t understand why she didn’t. It’s as if she hasn’t quite got the courage of her convictions.’