She moved along the wall to keep Cooper in sight. The ground wasn’t so wet now, but her feet still slipped on the bare, churned earth. Fry came across some abandoned construction work, trenches and spoil heaps left by Nikolai Dudzik and his men.

‘Even after the buildings come down, it’ll be a long time before this land is decontaminated,’ she said.

‘If it ever will,’ said Cooper, as if he was referring to something else entirely.

She didn’t question what he meant. Sometimes it was better not to ask, because the answers only left her more baffled than ever.

‘The demolition teams can’t get on site until after Christmas, of course. But it won’t take them long to bring this lot down, once they get started. I’m amazed some of these walls haven’t fallen down already.’

‘What about the construction crew?’

‘They’ve all packed up and left. They’ve got an extended break over Christmas, then their agency is sending them off to another job in Stockport. Except for Jamie Ward. I think he’s lost his taste for building work.’

‘I suggested he give my brother a call,’ said Cooper. ‘Matt will be able to find him some work for a couple of weeks until he goes back to university. Jamie has worked on a farm before, so he’ll be OK with that.’

Fry checked the back door of the farmhouse to make sure it was locked. She wasn’t sure whether she was responding to a concern about vandals breaking in, or an inexplicable instinct to prevent anything getting out.

‘Has your brother ever thought about diversification?’ she asked.

Cooper laughed. ‘Yes, he’s thought about it. He thinks about it the way a turkey thinks about Christmas. It’s going to come, but that doesn’t mean you have to like it.’

A piece of glass crunched under Fry’s foot. She jumped, imagining the poisons that contaminated parts of Pity Wood. Battery acid and anti-freeze, iodine and drain cleaner. A toxic mix that had contaminated the farm beyond salvation.

‘Ben, we shouldn’t be here at all,’ she said. ‘It’s much too dangerous.’

‘There’s just one thing, Diane.’

‘What are you looking for?’

‘I think I saw it around here somewhere.’

‘You should be wearing gloves and a mask.’

‘I’ll be careful.’

‘Famous last words,’ she said, watching him anxiously, but trying not to sound like his mother.

Cooper was poking about in some of the rubbish that had been discarded when the skip had been searched. Finally, he dragged out a long pole, with a rusted metal plate attached to the top.

‘What now?’ asked Fry, as he scraped away at the metal. She could see the remains of some white enamel and black lettering, perhaps even a crude picture.

‘The old Pity Wood Farm sign. I wondered where it had gone,’ said Cooper.