He looked up to make sure he could get Diane Fry’s attention.

‘I think some of Audrey Steele’s family were responsible for that arson attack,’ he said. ‘Revenge on Audrey’s behalf.’

‘Revenge for what? We don’t know what happened to her yet.’

‘It would be an emotional response, not a logical one. But they were understandably upset, and they had to find someone to blame. I think they heard all they really wanted to hear last time I visited Mrs Gill.’

‘I saw some of the family at the woodland burial,’ said Fry. ‘I bet a few of them are known to us. One of them was Micky Ellis’s brother, for a start. Let’s see if we can find any violent offences on their records.’

‘This is the Devonshire Estate we’re talking about,’ said Cooper. ‘If they didn’t carry out the arson attack themselves, they’re bound to know people who’d do it for a few quid.’

‘You’re right. But we need to put some effort into it. I’d like to feel sure in my own mind that Audrey Steele’s family were responsible. Otherwise, I might start suspecting that someone at Hudson and Slack did it.’

Cooper nodded. ‘It could turn out to be very convenient for somebody that the personnel files were burned.’

‘Exactly. I’ve asked Forensics to recover as much as they can. But the fire and the firemen’s hoses did a pretty good job between them, from what I saw.’

‘That’s an odd thing, actually,’ said Cooper. ‘Those filing cabinets were steel. They’re designed to be fire resistant, as long as you keep the drawers closed.’

‘Those drawers looked as though they were open when the fire started.’

‘Yes, I think they must have been, for the contents to burn like that.’

Fry looked at him. ‘No, it means nothing. The arsonists probably opened the drawers and threw the files on the floor to get a better blaze going, that’s all.’

‘Confidential files? The cabinets should have been locked, surely?’

‘We need to ask the office staff.’

Cooper looked at his watch and began to put on his jacket. ‘Well, let me know if there’s anything you want me to do, Diane.’

‘Where are you off to?’

‘I want to speak to Vernon Slack again. He’s frightened of something, and I’m going to find out what. And then I might tackle Billy McGowan.’

‘McGowan? Not on your own, you don’t. Do you hear me?’

‘OK.’

‘And, Ben – what about the dog?’

‘I talked to one of the officers working with Poacher Watch. According to local intelligence, lampers often operate on parts of the Alder Hall estate, but there have never been any complaints from the owners.’

Fry smiled. ‘How strange. What do you bet that Mr Casey is making a bit of money on the side by giving them access?’

‘Taking a cut from poaching gangs? It’s possible.’

‘It would explain why he wants to keep the place to himself.’

‘Maybe that ex-employee would have something to tell us.’