‘I’ll leave you to it, I’m just down the hall if you need anything,’ the care assistant says, and pulls the door after her.

‘Do I know you?’ Ruth Cavanagh asks, in a voice that crackles with age.

I had considered many options on my journey here but in the end, I’d decided honesty is best.

‘You don’t, but I live in the house once owned by Lily Murphy’s parents.’ I’m watching carefully for a reaction. Ruth’s expression doesn’t change. Her eyes stay on me, betraying nothing. On her lap, she clasps her hands together.

‘Do you remember Lily and her parents?’ I try, removing my phone from my handbag and placing the bag on the floor beside the bed. It’s hot in the room and I’m suddenly thirsty. On the nightstand, there’s a glass of water that looks like it’s gathering dust, and a full plastic jug beside it. A framed photo shows a man dressed in a suit, his face unsmiling. Mr Cavanagh, perhaps. A small silver dish sits in front of the photo, like an offering at an altar. In it are two emerald rings, a Miraculous Medal, a string of blue plastic rosary beads, and an earring in the shape of a cross. A memorial card – for Mr Cavanagh, maybe, faded with age. A dark red leather-bound notebook takes up the rest of the nightstand surface, and on top lies a silver pen.

I take a seat on the plastic chair opposite Ruth and try again.

‘Do you remember Lily?’

Ruth smiles. ‘Oh yes, a singer I believe. Back in the forties. Goodness, I loved her music.’

‘No, not a singer – she lived in the house behind you and went missing in 1985.’

Ruth shakes her head dreamily. ‘I don’t, I’m afraid. But I’ve just realized who you are. I met you at the newsagent’s yesterday, didn’t I? When I was buying my cigarettes? The shop on Kilburn High Road, the small one with the canopy.’ She claps her hands together and smiles triumphantly.

I smile back.

‘You might be mixing me up with someone else. But look’ – I hold up the Polaroid – ‘that’s your house, and that’s Lily Murphy. Do you remember?’

Ruth shakes her head.

‘Did you take this photo maybe?’

‘No, not me.’

‘Did someone else take it? Maybe someone sneaked into your garden and took the photo?’

‘Perhaps. Yes, I think so.’ Ruth still sounds dreamy but I decide to take her reply at face value.

‘Do you mean somebody may have sneaked into your garden, smuggled Lily in and taken her photo, all without you or her grieving parents hearing anything?’ I keep watching for a reaction. ‘The houses are back to back, remember, you can hear everything.’

‘That sounds lovely, dear. How’s your sister? I remember her when she was young, such a beautiful girl.’

‘I don’t have a sister,’ I say gently. ‘I’m here because of Lily.’

‘Ah good, and your mother?’ Ruth goes on, as though she hasn’t heard. ‘How’s she?’