But the police on traffic duty had closed off the entire stretch of road when the fireworks started, and Fry found lines of traffic were already backing up in both directions.

‘Oh, shit.’

‘Did Mullen get through?’ asked Cooper when she told him.

‘A CSO up here says a red Citroën went through like a bat out of hell just before they closed the road.’

‘It’s lucky I was on this side of the gardens. Georgi’s with me now, and we’re nearly at my car. Where do you suppose he’s going?’

‘He isn’t going anywhere, as far as I’m concerned. His car will be stopped when it reaches Cromford. There are two officers posted at the junction, with manual control of the traffic lights.’

Kotsev followed Cooper into his Toyota, and it bounced off the kerb as Cooper accelerated down the empty roadway.

‘He’s definitely heading south, Diane?’

‘Yes. There’s nothing else that way, is there? No other roads? No way he can dodge us?’

‘There’s just Masson Mill. It’s only three hundred and fifty yards downstream from the gardens, but he’ll be able to see the Cromford junction from there. He’s not an idiot – if he sees the uniforms standing at the lights, he’ll know what’s going on.’

‘Masson Mill? The shopping village?’

‘That’s it. He could turn into the car park at the mill – the walls are high enough for him to get out of sight there.’

‘OK. He might think we’ll go flying straight past into Cromford. We’ll probably find him sitting quietly with his headlights off, praying that we don’t stop.’

‘Let’s hope so.’

The central storeys of the mill were lit up, picking out Arkwright’s name on the brickwork. But the rest of the building and the roofs of the weaving sheds below the road were in complete darkness. At the entrance to the car park, a couple of attendants leaned against a wall, looking bored as they waited for owners to return for their vehicles.

Sensing that something was wrong, Cooper twisted his head round, and stamped on the brakes.

‘Damn. The Citroën is on the forecourt in front of the main entrance. I almost didn’t see it.’

Motorists in the queue of stalled traffic stared at him curiously as he reversed a few yards towards Mullen’s car. It was parked at an awkward angle between two other vehicles that had been left there when the Car park full signs went up.

‘He must have swung straight across the pavement as he went through the pedestrian crossing. And I bet none of these people noticed anything.’

‘They don’t look happy about the hold-up,’ said Kotsev. ‘Why should they report another driver for escaping it?’