He was so still that she knew he was going to try to take her by surprise and break free. If she had too firm a grip on him when he tried it, one of them would get hurt – and she knew which of them it would be. Fry didn’t want to find herself responsible for a suspect with a broken arm at this time of night; maybe ending up on the wrong end of an ABH charge in the morning when the suspect got to talk to a lawyer.

She increased the distance between them slightly and relaxed her grip just enough so that he would notice. Suddenly, he jerked his arm free, put his head down and legged it as hard as he could for the corner of the road. Probably he had a car parked somewhere out of sight.

Fry let him go. There was no point in chasing him, even if her leg hadn’t been hurting. She had definitely given him a scare, though. That was one weirdo who would think twice about following women in the future.

Ben Cooper managed to get Weenink moving again and they turned left at the top of the path and emerged on to Bargate. There was still some traffic passing across the lights a few yards away, where the pedestrianized area began.

‘Uh-oh, got to have a piss,’ said Weenink.

‘You’ll have to hold on.’

‘Can’t.’

Weenink began to unzip and stumbled into the doorway of Boots the Chemists.

‘Oh, Jesus.’ Cooper stood with his back to the doorway, watching the cars cross the end of Bargate, praying that none of them would turn down the street. The sound of a trickle turned into a steady stream, and a pool of urine began to run past his feet on to the pavement.

‘Hurry up.’

Weenink just grunted. Cooper swore under his breath as a patrol car appeared at the lights and stopped on the red signal. The car had the distinctive green and yellow checkerboard pattern on the side that indicated it belonged to Traffic division. Cooper wasn’t even likely to know the crew. Not that knowing them would help in the least.

He recalled travelling on the M1 one day with his father, back at the time of the year-long miners’ strike – 1984, it must have been. Ben had been fourteen years old, and he had gone with his father and Matt to a football match. Derby County had been playing Aston Villa at Birmingham in the FA Cup. He remembered the match well. But he remembered the incident on the motorway, too.