‘But Evie’s not the only link between the two men, is she?’ His voice was very low, so they had to concentrate to hear the words.

‘Tell us what you’re thinking, Jimmy.’ Willow leaned back against the desk and waited.

‘Jerry Markham seems to have been planning a story around Shetland’s energy. He asked his father to set up a meeting for him at Sullom, and he’d agreed to attend the action meeting called by the Walshes. He was sniffing around about the new gas terminal. And John Henderson worked as a pilot on the oil tankers. Another link. Not so personal. But more likely maybe than Evie Watt disposing of her men like a black-widow spider.’ He paused. ‘Maria Markham said he was working on something secret and he was planning to tell them the night that he died.’

‘So we’re back to Jerry Markham’s story,’ Willow said. ‘The one that was going to make his fortune. Except, according to his editor, there was no story.’

‘I’ve been thinking about that too.’ Perez was still tentative. It was as if, after standing up to her earlier in the afternoon, he didn’t want to come across as pushy or to undermine her further. She wanted to tell him to get over it – she wasn’t the sort to feel threatened by a colleague. But part of her still resented the fact that he was the one coming up with the new ideas.

‘Go on,’ she said.

‘What if the story wasn’t for publication, if he was researching for quite a different reason?’

‘Like?’

‘I did wonder,’ Perez said slowly, ‘about blackmail.’

As soon as the word was spoken it seemed so obvious that Willow was astonished, horrified that it hadn’t occurred to her. How had she ever thought she could do well at this business? Markham was a greedy man and he’d thought he could squeeze money from former contacts. But still she kept her voice even and didn’t let on what she was thinking. Years of practice, when the Uist kids laughed at her hippy clothes and called her names. ‘Well, yes, Jimmy. Of course that does make sense. So who was blackmailing whom here? And how does John Henderson fit in?’

Perez leaned forward now, joining in the circle, less of an outsider looking in. ‘As I see it – ’ his voice was hesitant and still so quiet that she struggled to make out the words – ‘Markham was the blackmailer. His blackmail victim was the killer. And Henderson guessed what was going on. Or was in the wrong place at the wrong time. Was driving past, maybe, when Markham’s car was forced off the road.’