But one of the figures paused as he passed between the rows of black vehicles. The other two turned, gesturing to him impatiently. With a ferocious swing of his arm, the biggest man brought down the blades of his bolt cutters and smashed the windscreen of a hearse. The toughened glass crazed, and he jabbed at it until it fell in fragments. Then he tossed the plastic container and the remaining petrol on to the driver’s seat and dropped in a lighted match. He laughed at the heat and shock of the explosion as he ran to join the others at the gap in the fence. They clambered over the wall and sprinted back the way they’d come along the railway cutting. A car was waiting for them in a back street near Chesterfield Road.

By the time the first fire appliance turned off Fargate, the three men were long gone. In the street, people who’d come out of their houses to watch the flames had to cover their mouths as the wind changed direction, blowing acrid smoke and flakes of ash into their faces. Something was burning well at Hudson and Slack.

Despite his best efforts, it was inevitable they would end up talking shop. The current point of contact between them was the mystery caller.

‘Diane Fry is taking these calls very seriously,’ said Cooper. ‘Very seriously.’

The lamb curry he’d chosen was good, not too hot. With a few side dishes, the meal was living up to expectations.

‘The tapes have really upset her, you know,’ said Petty.

‘They’re pretty awful. Nobody likes listening to them.’

‘It’s more than that with Diane.’

‘Is it? Why?’

Petty hesitated. ‘I can’t say. She told me in confidence.’

‘Oh?’

Cooper was surprised by a surge of jealousy. There had been occasions when Fry had confided in him. But very few occasions. It was some time ago now that she’d told him about her childhood in foster homes in the Black Country, about her older sister who’d been a heroin addict by the time she ran away from home and disappeared from Diane’s life. She’d talked to him about Angie again recently, too, but only because she had to. Cooper had somehow got himself involved in events that were nothing to do with him.

But that was really all he knew about Fry’s life. Most of the time, she seemed to be trapped inside a bubble of her own, a little capsule of isolation that no one could penetrate. Had Liz Petty managed to penetrate that bubble?

Cooper looked across the table at Liz as she scooped up her curry with a poppadom.

‘Do you get on well with Diane?’ he said. ‘How long have you been friendly with her?’

‘Ben –’

‘I didn’t think she had any friends at West Street. What does she talk to you about?’

Petty put down her fork and gave him a quizzical smile.

‘Ben, could we talk about something other than Diane Fry?’

Cooper felt his face start to grow warm. Perhaps the curry was too hot for him, after all.