For the second time, I am about to set off to 15 Megson Crescent. I’m not scared any more, neither of Mary nor of finding Aidan there. It will be almost comforting to have my worst fears confirmed, as I know they will be. A conspiracy: the hardest thing of all to forgive; conspirators who don’t care if you forgive them because they don’t care about you and never did.

Because there’s only one way that any of this makes sense: if Aidan and Mary are working together to drive me out of my mind.

I lock the workshop. As I pull my car keys out of my pocket, a scrap of paper falls to the ground: Charlie Zailer’s mobile phone number. I asked her for it last night; she looked as if she was going to say no at first. I pick it up, feeling guilty for ignoring her advice: Don’t go to Mary’s house.

I drive along the Silsford road, under the overhanging trees that lean in on both sides to meet in the middle—a tunnel of lush foliage. Where I am now it’s beautiful, but soon the trees will thin out, the road surface will deteriorate, and I’ll see grimy squat houses that make my lodge house look enormous. A little further on I’ll pass the primary school that’s made of grey-green concrete and looks like a prison block, and Bob’s Bargain Centre on the corner of the street that leads to the Winstanley estate.

Last time, I drove so slowly I must have looked like a kerbcrawler—anything to put it off. Today I slam my foot down on the gas. I want to get it over with.

Her house hasn’t changed. Aidan’s car isn’t parked outside, or anywhere else on Megson Crescent. I bang on the door. ‘Open up!’

Mary looks worse than I remember. That scored crêpe skin, the horrible woolly hair, like a knitted doll whose maker had a few balls to spare and got carried away. I want to wrench the ugly, coarse spirals out of her scalp one by one. ‘Ruth,’ she says, clutching the door with both hands, clinging to it as she pulls it back to let me in. ‘You came back.’ She’s surprised. Was she counting on my being scared for ever?

‘Where is he?’ I ask.

‘He?’

I barge past her, pushing open doors. There’s no one in any of the downstairs rooms. Only me and Mary in the hall. And the people in the paintings on the walls, the small woman with doughy skin and pointed features all bunched up in the middle of her face. In one of the pictures she’s looking in a mirror and her reflection is staring straight at me. She looks mean, as if she wants to accuse me of something.

‘Ruth?’ Mary touches my arm. ‘What’s wrong? Who are you looking for?’

‘Aidan. Where is he?’ I start to climb the stairs.

‘Aidan Seed? The man the police keep asking me about?’ Mary follows me. ‘I don’t know him.’