‘John Fowler was a writer and journalist. Respected. A freelancer, but he did OK at it and made a good living. It seemed unlikely that he didn’t know Angela Moore. They’re all obsessive, these birdwatchers, and the scientists even more so. Look at Ben Catchpole. They come across an area of research and dig away at it.’ Perez found himself feeling his way into the skin of the murderer despite himself. He’d spoken to Fowler’s former colleagues; sitting in the kitchen in Springfield there’d been long telephone conversations about the man’s state of mind. This was Fran’s killer, but Perez had never really believed in monsters. To dismiss Fowler as a monster would be to let him off the hook. It was better to understand him and force him to take responsibility.

‘After Angela published the work on the slender-billed curlew everything went wrong for him,’ Perez went on. ‘He lost his credibility. He tried to persuade a few people that the find was his, but who would believe him? Angela was young and attractive, a publisher’s dream. It would be much harder to promote a middle-aged man, with a reputation for claiming rare birds that had never existed. Everyone had a vested interest in dismissing his claims. He gave up work as a journalist and set up the bookshop. He told everyone he needed to de-stress.’

‘Did he see a psychiatrist?’ The Fiscal looked up sharply from the paper where she was making notes. ‘Is he fit to plead?’

Perez shrugged. It seemed to him that anyone who had killed three women could be considered insane. He blamed himself. I knew. I should have stopped it.

‘He came to Fair Isle with the intention of killing Angela Moore,’ Rhona Laing went on. ‘It was premeditated. Planned. He didn’t lash out in a jealous rage. Not manslaughter due to diminished responsibility. They can’t go for that.’

But jealousy had been at the heart of it, Perez thought. A slow-burning fury that had consumed Fowler, taking over his thoughts and his dreams, destroying him. Destroying the women who had stood in his way. Was that illness? Luckily it wasn’t for Perez to decide.

‘Go on, Jimmy,’ the Fiscal said, making some effort to control her impatience. ‘Let’s hear the rest of the story.’

He looked up and for a moment he wanted to hit out at the smooth, expensively made-up face. This was just work to her. Work and ambition. She’d take his words and use them to make herself seem clever. ‘Why? You know already. What am I? Your performing monkey?’

The outburst shocked her. ‘I’m sorry, Jimmy. Is this too soon? Do you want to stop?’

He shook his head fiercely. He couldn’t bear her pity.