The police formed a wall and turned to face their attackers again. Beyond the opposing lines, Cooper could see the main buildings of the High Peak College campus, set on the lower slopes of the hill. They looked down on Edendale like benign giants, the educational heights of the Eden Valley.

He began to search his pockets for a packet of mints to take the taste of nausea from his mouth. He had a lot of pockets – in his jeans, in his checked shirt, on the inside and the outside of his waxed jacket. But all he found was a scatter of cashpoint receipts, two empty shotgun cartridge cases and half a packet of dog biscuits.

Cooper knew there was more than just education that went on in those college buildings on the hill. He had been there himself, for long enough to collect the A-levels he needed to get into the police service. His fellow students had accused him of being single-minded, as if his determination made them guilty about their own pursuit of parties and casual sex. But there had been a demon driving Ben Cooper that his contemporaries would never have understood – a jealous God who would not have tolerated parties.

Dave Rennie sat back comfortably in his seat and unscrewed the top of a vacuum flask. He offered Cooper a plastic cup, which he refused as soon as he got a whiff of the metallic tang of the coffee. The sergeant’s expression was serious, his forehead creased with anxiety, like a man with a great responsibility on his mind.

‘You see, if they get rid of the kitchen and sack the canteen staff, that means they’ll put vending machines in instead,’ he said. ‘And then what would happen? I mean, would anybody use them? There’s no point in spending money on vending machines if they don’t get used. It would look bad in the budgets, wasting money at a time like this.’

Cooper watched Todd Weenink duck his head and drive his shoulders forward to meet a wiry-haired youth who’d been tormenting him all afternoon. There was a thud as their skulls connected and a scuffing as their feet lashed out.

The crowd behind Cooper began yelling. Then the police back-pedalled. Officers fell and were trampled as they lay on the ground. But Weenink broke away and looked around, bemused. His eyes were dazed, as if he might have taken a knock on the head. Then he looked up and caught sight of a student running past him, and made an instinctive grab. The student’s legs folded beneath him under the impact of Weenink’s sixteen stone, and they both sprawled in the mud, exhausted and gasping.