He shoots me a wink and I nod back, dumbly. Even though I was expecting to see him, that now-familiar sense of confusion and nervous excitement is thrumming once again in my chest. There’s so much I need to ask him.

The old man plonks three mugs of tea down next to Harv’s half-eaten sandwich, and settles in the chair opposite me. ‘So, I told you we’d meet again, didn’t I? What’s on your mind this time?’

I look back at Harv, who’s blowing the steam off his mug of tea as he stares around him. The idea of bringing him along now seems utterly, obviously insane. I mean, how am I supposed to have this conversation in front of him?

The watch-seller reads my mind. ‘Don’t worry about your friend here,’ he says. ‘Back in the present, he won’t have any memory at all of this encounter taking place. It will be like it never happened.’

‘Er … what was that, mate?’ Harv says.

The watch-seller grins and glances down at Harv’s belly. ‘You’ve filled out a little since I last saw you.’

Harv’s mouth forms the ‘W’ of ‘what’, but no sound comes out. Despite everything, I find I’m quite enjoying the novel sensation of not being the most bewildered person in the room.

‘What is going on, Ben?’ Harv demands. ‘Seriously, who is this dude?’

The watch-seller answers for me. ‘In the year 2020, I gave your friend here a wristwatch that allows him to revisit various moments in his past. He’s reliving one of these moments right now, and I assume he’s here because he wants my advice.’

Harv continues to stare at him blankly, his mouth a perfect straight line.

‘It’s true, Harv,’ I find myself saying. ‘It sounds mad, obviously …’

Harv sniffs and takes a gulp of his tea. ‘Look, if you’re both gonna be twats, I’ll just go to the pub.’

I turn back to the old man. ‘Will he really not remember this?’

The old man shakes his head.

‘So, nothing I do in these moments will have any effect in 2020?’

‘Not directly, no.’

‘What. Is. Going. On?’ Harv thumps the table with every word, making the mugs rattle. ‘Is this some kind of prank? Are we being filmed or something?’

‘Do you really not remember?’ I ask him. ‘When we talked about time travel, the night of Marek’s play at uni? Before we played Sardines in the maze? You came with me to the Drama Barn because I was so late. And before that, we talked about Groundhog Day in the kitchen.’

Harv narrows his eyes. ‘No … that’s not what happened, Ben. I only saw you later, after the play. And we definitely didn’t talk about Groundhog Day. I would remember if we did, because I bloody love that film.’

The watch-seller nods. ‘Great film.’