We find a table in a corner. It’s private enough, but the canteen is noisy, every clink and clatter echoing off the walls, voices rebounding all around.

I suppose all hospital canteens look similar, with their clusters of families grouped at the tables. There’s a family of five not far from where we’re sitting: a mum and dad, a teenage girl and two younger boys. I wonder who they’ve come here to visit. A grandparent maybe? Another sibling?

I look across the table at Alastair, trying to concentrate only on him. ‘Are you a nurse here?’ I ask, and Alastair shakes his head.

‘A porter. I take the children round the hospital, wherever they need to go.’

‘You were working here when you knew Sarah too?’

Alastair shakes his head. ‘No. Before that. I knew her from university.’

‘You were at university together?’ I don’t know why this should be a surprise. Why I’d imagine Sarah wouldn’t have had a degree. ‘Where?’

Alastair hesitates for the tiniest moment. ‘Middlesex,’ he says. ‘But I wasn’t—’ Over my shoulder, someone drops a piece of cutlery and it clatters against the floor. I can’t help glancing round.

Alastair pushes aside his paper cup. ‘I’m sorry,’ he says, ‘I’m not making sense of any of this. You say Sarah died, and you’re trying to trace old friends …’

I breathe slowly, carefully. ‘I was the housing manager for the flat where she lived. I wasn’t the one who moved her in, but the flat was on my caseload and … I was there when they found her. I don’t know if you saw the story in the news – about the woman in Brixton and how – and how …’

Alastair is looking at me. Steam from our drinks blurs the air between us. He says, very quietly, very slowly: ‘That was Sarah? My Sarah?’

‘Yes.’ It feels as though the room around me is spinning. I wish that I had slept more last night. I’m not at my best at all.

‘You’re going to have to give me a minute,’ Alastair says.

The canteen suddenly seems busier, noisier than ever. The racket sets my body on edge. I should tell him about the email Sarah sent me and the fact that I knew her, years before, but suddenly I find that I can’t. Suddenly, I feel horribly, horribly responsible. The look on Alastair’s face is awful.

‘I’m sorry,’ I say. ‘I’m really sorry to have come here and told you this.’

Alastair shakes his head. ‘I’d have wanted to know. I’m just … it just … I feel so awful. I mean, I feel sick. I think I’m in shock.’

I don’t know what to do. Didn’t I know this might happen? I try not to move a single muscle. Maybe he will simply want me to go away. Maybe he will get angry with me, shout at me, tell me I’m a terrible person for coming here. I clench my jaw, preparing myself for any possibility. But in the end, Alastair just lets out a long, shaky breath.