‘Yeah,’ I said. ‘But we’re here now. Could we go for a coffee or something? We’ll pay.’

Lucas sighed. He had one of those strange body shapes that I thought meant he went to the gym every day. He was very tall and very broad, but the muscles on his upper body were so developed that he looked as if he was going to tip over, while his legs were quite small. His hair was cut very short, but although all those things added up to quite a scary figure I didn’t feel that he was dangerous, particularly not if we were going for a coffee in a public place.

‘OK, girls,’ he said. ‘For Joe – of course. I’m off to the gym and I’m all psyched for it now, so I don’t want to bail. I’ll meet you in in an hour, OK? Since you want to see the canal, let’s meet at the cafe down there. Turn right here and then left on to the path and you’ll see it in front of you. Hour and twenty maybe?’

‘I don’t think it was him.’

Izzy nodded her agreement. We were waiting at the cafe, at a table in a corner, watching people cycling and running and walking their dogs and children down the path. We were meant to be revising, but really we were people-watching and talking about Lucas.

‘Yeah,’ she said. ‘He didn’t look guilty, did he? He didn’t have an air of …’ She made swirly patterns in the air with her fingers. ‘Oh no! My past has finally caught up!’

‘He was pleased to talk about Joe, if anything.’

I looked at our list of questions. We were prepared for this. Lucas would probably be ages at the gym. We had exams coming up. I pushed the list aside reluctantly and picked up the revision guide.

‘So,’ I said. ‘Themes of power and guilt, right?’

An hour and a half later he joined us at our table, holding some kind of herbal tea in a china cup, and we pulled our attention away from ‘Ozymandias’.

‘Right,’ he said. ‘Joe Simpson. Here’s what I’ve been thinking while I pumped iron: why me? I only knew him for, what, a year and a half? Devon must be full of people who hung out with him from when they were babies. And we weren’t even very close. Why doorstep me, girls? Or are you going after everyone?’

‘Weren’t you close really?’ I said. I tried to look innocent. ‘Gus said you were one of his friends. He thought Joe spoke to you on the day he disappeared?’

‘Seriously? I guess he’s right about that, but we weren’t best mates. You need Troy for that. Have you contacted him?’