I knew what a standard trope it was for a crime novel, one that had fallen from favour because of over-use, exactly like locked room mysteries and attempts to commit the perfect murder. They too were classic stories of the past.

But my position kept shifting. I would recover my confidence and something about Lew Antterland’s death would grab my interest again.

Jo listened, then said: ‘Maybe this means there was more to the murder than you’ve realized.’

‘I’ve tried to see it that way.’

‘This woman cop you met on Dearth – she told you that long story. There must have been a reason.’

‘An ulterior motive?’

‘I don’t know,’ Jo said. ‘I haven’t read it, of course. But was she trying to tell you something else?’

‘I thought that too. I simply didn’t know her well enough to read her intentions properly. At the time I wasn’t paying attention, mentally fending her off because I’m fed up with people trying to describe their rotten ideas for books. I was listening to her but not paying proper attention. It was only yesterday, when I transcribed the recording, that I began to wonder what was going on.’

‘You always say that’s where the real interest of a crime story lies. Not in the mystery the plot seems to be about, but what is not being told, the undercurrent. You once described it to me as the darker world of unadmitted motive. The story the killer didn’t intend to reveal, the one the detective misses, and only spots belatedly.’

‘Yes,’ I said, suddenly alert again. I needed Jo to remind me of these things.

‘That’s what makes your novels different, Todd. But this Antterland murder has made you think like an amateur sleuth, isn’t that right? You always say you shouldn’t do that. It’s the wrong way to make crime interesting.’

‘Yes,’ I said again.

‘Now you’ve solved a mystery from fifteen years ago, one few people have ever heard of, let alone will care about. What’s the real story behind it? The one you should be interested in. The one you might be able to write?’

‘I suppose that’s what I’ve been looking for,’ I said, feeling chastened. Jo knew my work better than I did.

‘Your last novel broke new ground,’ Jo went on. I glanced across at the page proofs, about a third read so far, the rest of them yet to be checked. ‘You said that book, when it comes out next year, will move you further away from the standard genre stuff, and the new novel—’

‘I’m still working on it. I’d be writing it now if I hadn’t had to go away for a week.’

‘OK,’ Jo said. ‘Then can’t you forget this old stuff and get back to it?’