‘Even though she’d probably guessed some of it, guessed at least that Markham was in Shetland to pass on some gossip about Henderson. And she can’t have cared, can she? She went out, got pissed and then decided it didn’t matter. The next day she was behaving just as normal. She loved him and was going to marry him anyway.’ Willow looked up at the men. ‘Such a dreadful waste! What did Markham think he would achieve?’

‘Henderson made the mistake of phoning Francis first,’ Perez said. ‘To warn him that Evie might be too upset to marry him. He’d have thought it was the honourable thing to do. The men were old friends. And perhaps something in Watt’s response to the call made John suspect he was the killer.’

‘So Henderson had to die too.’

‘He did. And perhaps by then Francis saw himself as a kind of avenging angel. He must have convinced himself that this was for the best, that Evie didn’t deserve an adulterer like Henderson after all. This time there was an even more elaborate crime scene. Henderson next to his wife-to-be, with the mask over his head.’

Willow took another drink. ‘A forensic psychiatrist will have a fine time with that!’ She looked into the fire. ‘Jessie had nothing to do with that killing. Francis left home early and was just home by the time you visited them that afternoon, Jimmy. Jessie was working in the fields all day. She didn’t ask where Francis was going in his boat. She didn’t want to know.’

They sat for a moment in silence.

‘In the end I think Watt blamed Rhona Laing for everything,’ Perez went on. ‘She seduced Henderson, not caring that his wife was dying. She began the whole business. In Francis’s head, she’d even turned him into a killer.’

Perez sat back in his chair. ‘I saw Evie this afternoon,’ he said. ‘She’s staying with Jen and Andy Belshaw.’ He thought of the young woman’s fury, her blazing eyes and violent words. Hatred of her parents was helping her through her present grief, but that wouldn’t last.

Perez wanted his visitors to go now. He was tired and needed to be left with his own thoughts and his own memories. The others must have realized that, because suddenly they were on their feet, and the door was open, and the chill night air was in the house.

Sandy went ahead of them, almost running down the bank to the car. Perez decided that he definitely had an appointment with a woman. Willow stood for a moment. ‘I’m away south tomorrow,’ she said. ‘My father’s birthday. I’m off on the first plane, so I’ll not see you.’

‘But you’ll be back?’ There was a moment of panic. He saw how much he would miss her.