On the way back, they had come up at the rear of a long convoy of coaches, one behind the other, travelling in the inside lane of the motorway. They all carried the name of a coach operator in London and they were packed with men, like some factory outing. When the Coopers’ car was close behind the last vehicle, every man on the coach stood up on the seats and dropped his trousers. There was a sudden blooming of white buttocks like exotic lilies in a pond as the men mooned through the windows at passing motorists.

Ben and Matt had laughed, until their father became angry, then pulled out and began to overtake the coach. Maybe he had intended to pull the driver over, Ben wasn’t sure. But Sergeant Cooper was off duty, and they weren’t even in Derbyshire. This had been Nottinghamshire, somewhere south of Junction 27.

At some point, Ben had sensed his father change his mind. His foot had slipped off the accelerator. He had fallen back momentarily, then accelerated again and passed the convoy as quickly as possible. The boys said nothing. As they passed, they could see the uniforms. They could see the stickers in the front window of every coach. Ten coaches there were – they counted them as they passed. ‘Metropolitan Police’, the stickers said. They realized that the men were reinforcements arriving to help control the mass pickets of Yorkshire miners then threatening Nottinghamshire pits. Law and order was on the road.

The lights changed and the patrol car had moved on by the time Weenink reappeared.

‘Have you got any beer back at your place?’ he asked.

‘What is it you’ve done, Todd?’

Weenink’s mood was changing again, the cold air sharpening his tone. ‘It happens all the time, Ben. You’re not so innocent as you make out. You must know. I bet you’ve done it yourself.’

‘I don’t know what you’re talking about.’

‘I’m talking about a little bit of evidence being improved here and there. It happens. Everybody knows that it happens. Where’s the harm? As long as you don’t get caught.’

‘But –’ Ben Cooper struggled to capture all the reasons that ran through his mind why this was inconceivable. He thought of words like justice and integrity, like responsibility and honour. He thought of concepts like loyalty to your service, like honesty and truth. And self-respect. And he looked at Todd Weenink and knew that it wasn’t worth mentioning even one of them.

‘I can’t believe that you’re telling me this.’

‘I’m telling you because you asked me. And because I know you won’t shop me.’

‘How do you know I won’t?’