Holm shrugged. To be honest, he had no idea. The truck could stop anywhere. All it took was a couple of minutes to open the back doors and Mohid Latif and his companion could scramble out and be off.

After an hour the lorry was at Cambridge, and as the road bent to the right Holm settled in for a long drive. They were closing on the A1, the main trunk route to the north, the destination surely either northern England or Scotland. However, twenty miles up the A1 Holm was surprised when the lorry abruptly turned off the main road into a small industrial estate. Dim lights on low poles glowed in the dusk. Beyond the estate there was a succession of identical buildings and a tall chain-link fence.

‘What the hell is this place?’ Holm said. The lorry had stopped at a barrier next to a security box. Beyond was an area of hard standing and a large warehouse. Inside the box a solitary figure stood in a blaze of yellow light. To the right of the box a number of shipping containers were stacked two high. After a moment or two the barrier hinged upwards and the lorry drove in.

Javed was head down over his phone. ‘RAF Wittering.’ He looked up. ‘At least the bit behind that fence. This looks like some kind of business park attached to the base. Probably aerospace industries related to the airfield.’

‘This is crap. We’re going to get spotted here.’ Holm turned his head. A few car lengths back they’d passed a gate to a field full of head-high maize. He reversed the car, relieved to see the gate was open. He drove in and parked behind a hedge. ‘Have to do. Come on.’

Holm was out of the car and making for the warehouse on the field side of the hedge.

‘Boss.’ Javed was right behind, stumbling in the now near darkness. ‘We’ve got to be careful. We could get shot if we venture onto the base.’

‘Forget the base.’ They’d reached the corner of the field. Through the hedge they could see the truck backing up to the warehouse. Huge double doors stood open, blackness within. The truck inched inside, its reversing lights illuminating pallets and wooden crates and some sort of racking system. In the security box the guard had returned to reading a magazine. ‘This has nothing to do with the military. Now give me a bunk up.’

The fence was a couple of metres high but there was no barbed wire. The barrier was a deterrent rather than an impediment. Javed cupped his hands and Holm stepped onto the makeshift step. He grasped the top of the fence and hoisted himself up. The edge of the fence dug into his stomach and ripped his shirt, but he swung over awkwardly and dropped down the other side. Javed pulled himself up and over in one smooth movement.