Fry seemed to shake herself out of some reverie. ‘Fine. Look, I understand now what Vernon meant about the dead place being in other people’s hearts,’ she said. ‘But there had to be a physical place too, didn’t there?’

‘Where else for him but his own home? The house he grew up in, the place he associated with his parents, particularly with the man he’d always hated so much. This house was always a dead place for Vernon.’

Fry was quiet for a few moments. Watching her, Cooper knew she’d return to the same subject that had obsessed her all along, though he didn’t know why.

‘Those messages he sent,’ she said. ‘The gibbet and the rock, and all that. Do you think Vernon was hoping we’d work out the clues in time and stop him?’

‘We’ll never know, will we?’

‘If he was, Ben, we were too late.’

There was nothing Cooper could say to that. ‘Too late’ were the saddest words in the language, and they both knew it.

‘Was it Rod Stewart?’ he said.

‘What?’

‘That line from a song. “I’m not quite as dumb as I seem”.’

‘I don’t know any Rod Stewart songs,’ said Fry.

‘Come on, you must do.’

‘Well, I hope I don’t.’ Fry shivered suddenly. ‘Bloody Freddy Robertson. He could have saved us so much time. Why didn’t he tell us what he knew?’

‘This Lucy Somerville, his daughter,’ said Cooper. ‘I imagine she’s an only child?’

‘Yes. Why?’

‘It means Professor Robertson never had a son of his own.’

‘Oh, I see.’

‘And Vernon never had a real father. Not one that he cared about.’

‘So Robertson became a father figure?’

‘Very much so, I think. It’s all in the journal, Diane, when you have time to read it.’

Fry glanced at the book on the table. ‘I’m not sure I want to read it.’

‘Believe me, it’s all there. Robertson’s big mistake was to come here to Greenshaw Lodge at the wrong time. He chose the moment when Vernon’s faith in him had been destroyed. As far as Vernon was concerned, his substitute father had let him down, too. Robertson was killed with a rifle, not a shotgun, wasn’t he?’

‘So the doctor says. A single bullet, close to the heart. Enough to cause fatal internal injuries and major blood loss.’