‘What do you think did happen then?’

Lucas looked at both of us in turn. I could see him trying to decide whether to say it or not.

‘Can we turn this thing off?’ he said, nodding to Izzy’s phone, and she stopped the recording. ‘I hate to say it, but I’ve always thought someone killed him. Or kidnapped him. It’s the old Sherlock Holmes thing. Eliminate the impossible, and whatever remains must be the truth. My feeling is that he was abducted because of the way he vanished without trace. That doesn’t happen by accident. I did try my own detective work in the early days, but I didn’t get anywhere. I mean, I had no idea where to start. Who would kill Joe Simpson? The only person he didn’t like was me, and I didn’t do it. I was pretty sure no one in his family had done it. And people just don’t plot to murder normal teenage kids. He’s not, like, an heir to a fortune, or whatever might draw the attention of proper bad guys.’

He looked up at the ceiling. ‘God, it’s weird going back over this. So, if you rule out suicide, which I tentatively do because of the note thing, and if you rule out someone plotting to murder him because there’s no one, really, who would have done it – that kind of thing doesn’t happen in downtown Devon – then you’re left with a few things. Either he died by accident in a way that meant his body was never found, so probably involving the sea, or he was kidnapped. Or else someone killed him by accident, or on purpose, and did an excellent job of getting rid of …’

He blinked. ‘Sorry. You’ve taken me right back. I was obsessed with this. I became paranoid about attackers. That’s why I decided to get fit. I was ahead of the curve with the gym stuff.’ He rolled his eyes. ‘Don’t put any of this in your article. None of it, yeah?’

‘No,’ I said at once. ‘The article will be short. I’m actually getting really interested in this too, in its own right. I know I didn’t know Joe.’

Sorry, Joe, I added in my head. I do know you. I love you.

‘But I feel like I did, and I can’t believe this whole thing is just hanging there. It’s so strange.’

‘Isn’t it? I didn’t sleep for years just thinking about it. There wasn’t a robbery at Beachview. No obvious bad guy skulking about. There’s just nothing. I have no idea. Where would you dispose of a body?’

‘The sea,’ said Izzy.