Mole crickets, Perez thought. Fowler was still trying to interest the scientific world in his story. There’d been a letter saved on his computer, but none of them had recognized the significance.

Hugh continued: ‘Fowler was an amateur lister, in a hired car, wandering across the desert, hoping for the big story to make his career as a natural history journalist. He didn’t even have a degree! She had a PhD and a research budget and he beat her to it!’

‘But he never got the glory he deserved.’ Sandy again. That’s just what I might have said, Perez thought. You’re just speaking my lines.

‘Angela published first. And who was the establishment going to believe? Fowler already had the reputation as a bit of a stringer. Angela made sure nobody took him seriously again by spreading rumours around Shetland about rare birds he was supposed to have claimed. He became a laughing stock.’

It became his obsession, Perez thought. At first I thought he was driven by the need to see birds, like the twitchers who piled into Fair Isle to see the swan. But it was about revenge. He blamed Angela Moore for everything that had gone wrong in his life. For the dead baby and the dead marriage as well as all his lost dreams.

‘And you thought you’d take advantage of the situation?’

‘I’d always wanted to visit Fair Isle. I’d run out of money and my father refused to give me more.’ Hugh looked up and Perez saw an attempt at the old smile. ‘Tight bastard. He could have afforded it. So yeah, I thought it was worth a go. I wasn’t greedy, only asked for a couple of grand to tide me over. I didn’t expect Fowler to turn up though.’

‘That must have been a shock to Angela too.’

‘You could say that! Maurice took the booking and suddenly Fowler was there in the common room when she came through to do the log. But Fowler was pleasant to her. Polite. Calm. He certainly didn’t give the impression that he was out for revenge. Maybe she thought he was a good man, who wouldn’t harbour a grudge. He went to church every Sunday. Perhaps he was into turning the other cheek. She was jittery though. Everyone thought she was moody because Poppy was staying in the lighthouse, throwing her tantrums, but that wasn’t it at all.’

‘What I don’t understand,’ Sandy said and there was something steely in the voice Perez had never heard before, ‘what I really don’t understand, is why you didn’t tell us about this before. Two women dead and you knew a man had a motive to kill them. We could have had this cleared up days ago. A third woman need never have died.’