He heads off and I’m just about to shout after him decaff! when my mobile rings. When I pull it out, it’s Marianne’s name on the screen. I take a couple of breaths to steady myself. Should I tell her now, over the phone, about Sarah’s parents? After what it did to Alastair? Should I wait to visit her, or will that take too long; would she want me to tell her as soon as I could?

‘Marianne?’ I say when I answer. ‘Marianne, you’ll never guess—’

But she is already speaking over me. ‘Jennifer, you said you were going to see Alastair again?’

‘Yes? Why?’

‘I did some research. You said he and Sarah were together at Middlesex. A friend of mine works in the admissions office there. I had a hunch, I just wanted to check. I called to find out when they attended. It’s true, Sarah was there. She studied English and Creative Writing.’

‘Yes, I know. Alastair told me.’ I can see him at the open café, giving his order at the counter.

‘He told you?’

‘Yes. That’s how they met. That’s where they went out. Marianne, what is this about?’

‘Jennifer. He was never there.’

‘What?’ I can see Alastair heading back towards me, two takeaway cups of tea in his hands.

‘He’s not on any of their registers. Jennifer—’

‘I’m sorry, Marianne, I have to go.’ I let the phone slide from my ear. He lied to you, says the voice in my head. Yes, I reply. But I lied to him too.

‘Here you go.’ Alastair is looming over me, holding out the steaming cup. Automatically, I reach out to take the drink he has bought.

‘Are you okay?’ he says. ‘Jennifer, what is it?’

‘I’m sorry,’ I say, stumbling to my feet. My bag slips from my shoulder and I yank it back up. ‘It’s just the time. I have to get back to the office. I’m late, I’m sorry. I really have to go.’

‘Will you let me walk you back then, at least?’

I force a smile. ‘No, honestly, I’m literally going to have to run. You stay here. Enjoy the sunshine. I’ll call you later.’

And I hand back the tea and leave him there, standing in the park, staring after me as I rush away.

At the bottom of the stairs in our building, I hold onto the banister and force myself to catch my breath. I didn’t eat more than two bites of my sandwich, but my whole stomach feels swollen and distended, crushing up against my lungs.