‘I think the man’s an idiot, but he looked angry rather than scared. Do we have any idea what he’s hiding?’

‘We’re checking the public CCTV for the evening, trying to follow his car route. His wife gave us more accurate, detailed information, so I’m sure she’s no part of it. There’s motive, for sure, though. Leaving his whole estate to a charity was always going to cause a problem,’ Graham said, standing up.

‘Yes, but Andrew Jenson already knew he could challenge the will in court and he’s got a reasonable chance of winning, even with the psychiatric report,’ Ava said, doing her best not to comment on the rape charity issue itself. ‘Find out where he was and what he was doing. That’s the fastest way to exclude him from the investigation and shift the resources to where we’ll get results. Good work, both of you.’

Ava left, trying to keep her pace normal, knowing discussing the case with Callanach was inevitable. The real question, though, was not how Callanach was going to react to the news, but what she was going to do with the knowledge she had.

Chapter Eighteen

10 March

Callanach handed Rosa Macmillan a box of tissues.

‘I’m not sure which is worse,’ she sniffed. ‘I know that sounds awful, but he seemed to be going through a good period, so when I was told Stephen had killed himself, I started doubting everything I thought I knew about him. Then when I was told that somebody might have killed him … why would they? He was struggling enough just to survive.’

‘Did Tantallon Castle have any particular meaning for Stephen?’ Callanach asked.

‘Not that I was aware. I’m sure he said he’d been there, probably a school trip or something like that, but not recently. And as for going there at night when it was closed, that was totally out of character.’

‘He waved a knife around in the taxi on the way to Queensferry,’ Callanach reminded her. ‘So would it be fair to say his behaviour was becoming more erratic and unpredictable?’

‘Not as far as I was concerned. He was back on his medication. I know he felt terrible about what he’d done in that taxi, and he was worried about whether or not he was going to be prosecuted, but he was ready to take responsibility for it and his doctor had agreed to write a medical report if needed.

‘Stephen and I were talking regularly, seeing each other occasionally. I wasn’t ever going to be his girlfriend again, it was all too painful for me, but he’d let me back into his life. For the first time, he was thinking about his future, maybe getting some new qualifications, booking a holiday with one of those tours that takes groups of people to South America or Australia trekking. There were real signs of improvement.’