After working through thousands of more sophisticated ideas than this one we had settled on something as close to the truth as possible. It was important that he shouldn’t think we were interested in him in a sexual way (gross), and this was the best we could manage. Invoking the authority of the school, implying that some teacher was overseeing this, felt like a safety net.

‘Maybe we will even write an article about him,’ Izzy had said.

‘If there was a school magazine,’ I’d added, ‘then they might even have printed it.’

‘So it’s practically true.’

Now I watched Lucas, who was, for lack of any other ideas, our main suspect, to see if anything flickered over his face. All I saw was surprise. He hadn’t expected to be accosted in the street and asked about someone from twenty years ago, which was fair. There didn’t seem to be any panic or guilt, but that didn’t mean anything. If you could kill someone and hide it for twenty years you’d have a good poker face.

Then his expression changed again. He smiled. All of a sudden, he looked nice.

‘Joe Simpson!’ he said. ‘God. Blast from the past. Poor Joe. Have they found out what happened?’

‘No,’ I said. ‘We’re just doing this story because we, the school, want to mark the twenty-year anniversary. I mean, I know it’s technically past, but close enough. I think his family are keen that he shouldn’t be forgotten.’

Lucas nodded. ‘And you’ve spoken to Gus? How’s he doing?’

‘He’s OK. He’s got a lovely partner and two daughters.’

We seemed to be walking down the road with him. I couldn’t help noticing that Lucas hadn’t agreed to an interview, but at the same time he hadn’t told us to go away either, so it was probably best to keep talking.

‘How did you find me?’ he said. ‘This doorstepping thing. It makes me feel quite famous and all, but … couldn’t we have done this over email?’

I didn’t know what to say.

‘We could have emailed,’ said Izzy, ‘but we were in London anyway, on a day out, and when we looked you up and your address was right there we thought we’d try popping over to see you. Haggerston’s cool and we wanted to come here anyway, to walk the canal path.’

I hadn’t even known there was a canal path. This new confident Izzy was amazing.

‘You looked me up how?’

‘Electoral roll,’ I said, and he laughed.

‘I knew I should have ticked the box that keeps it secret,’ he said. ‘Look, I don’t want to be a buzzkill, but what are you, fifteen? Sixteen? You might not want to go turning up at strange men’s houses miles from home on a Saturday afternoon. Email is safer.’