‘Possibly. They have concerns. And, Meg, there’s another thing. Someone had listened to the message that Bex left on Kirsty’s landline, saying she was in the barn.’

‘What? Who listened?’

‘Kirsty was the only one home.’

‘Oh God.’ I paused and then whispered, ‘If it’s arson and Kirsty was the only one around, and she knew Bex was in the barn …’ I took myself further down the hallway, further from Bex.

‘I looked at the house-to-house again,’ Fiona said. ‘There was a woman who remembered Kirsty having problems as a child. Behaviour problems. She saw a psychiatrist. But nobody talked about it because she was Tony Nightingale’s daughter, and he’s like the country gent round here. The landowner. It was a throwaway comment, but it totally made my ears prick.’

‘What kind of behaviour problems?’ I already had my suspicions.

‘It’s not very clear. Even now you can see people don’t want to talk about it.’

It was a thing I’d noticed in some Derbyshire villages. A deference to the land-owning classes. As if the fact that your great-grandfather made a load of money exploiting peasants somehow made you more worthy. I remembered Gary’s wife, Mandy, saying Tony Nightingale had given money to the abattoir. She’d put it down to him wanting to keep everything nice in the village. But what if there was more to it than that? Was Tony paying a price for the villagers’ silence about his daughter?

I wasn’t surprised Kirsty had had behaviour problems as a child. I’d sensed something off with her from the start. The question was how these ‘behavioural problems’ manifested now.

‘Thanks, Fiona. Can you make sure we’ve got a good police presence at the hospital with Kirsty, in case she comes round.’

I ended the call and walked back to the kitchen. Bex was sitting at the table staring into space. She jumped when I came in.

‘What’s going on?’

In my mind’s eye, I saw Kirsty’s coldness when watching her barn burn, her attitude to her daughter and her sister, Gwen Twigg’s fear. I replayed the comments from people in the village about her. She could easily have killed Daniel by doctoring his painkillers, since she supplied them, but there was absolutely no evidence linking her to Gary’s death – or Violet’s, assuming she was dead.

‘Bex,’ I said. ‘Have you ever had any concerns about your sister’s behaviour?’

‘My sister? Not really.’

‘Did your dad ever have concerns? We’ve been told he took her to see a psychiatrist when she was a child.’

Bex frowned and shifted away from me. ‘No. But if it’s Dad, he’d have kept records. Follow me.’

She led me down a panelled corridor and into a musty-smelling study. The walls were lined with books – mainly leather-bound with gold lettering on their spines.