‘Unless you were about to suggest a better idea?’

Fry took the cue. ‘Well, if you like, I’d be happy to take you to dinner tonight and show you a bit of Edendale. As it happens, I’m free.’ He opened his mouth to reply, but she rushed on. ‘Well, it’s preferable to sitting on your own, isn’t it?’

Kotsev bowed slightly. ‘A great deal better, Sergeant. Thank you, I would be delighted.’

She let out the breath that she hadn’t realized she was holding until then.

‘I’ll pick you up here at about seven thirty, then.’

‘Seven thirty. Excellent. Goodbye for now.’

He insisted on shaking hands again. Then Fry watched him walk to the lift, rolling his shoulders a little under his leather jacket as he shifted the weight of his case. Kotsev pressed the button, and glanced back while he waited. Fry was surprised to find herself still standing there like an idiot. She waved self-consciously. But he was already turning to enter the lift, and he probably didn’t see it.

‘Ciao,’ she said quietly, as the doors closed behind him.

‘The device was taped under the chassis and wired into the electric motor for the ramp. Unloading the ramp closed the circuit and detonated the device. Click, boom. Simple, but effective.’

The army bomb squad captain looked pleased with himself, as if the device had been his own design and he’d scored top marks in his assessment. In his fatigues, he looked alarmingly young to be in charge of the combined briefing at Chesterfield police headquarters.

‘How big a device?’ said Hitchens. ‘I mean, how much explosive?’

The captain shrugged. ‘Twenty pounds or so. We can give you a better estimate later. But, to be honest, it didn’t need to be any bigger to achieve its primary purpose.’

‘Which was?’

‘Well, it looks pretty clear to me. I’d say the purpose was to take out the owners of the vehicle – not to maximize casualties or cause general devastation. This wasn’t al-Qaeda, you know. We’re not talking terrorism here.’

‘We’re not?’

‘In my opinion, the attack was targeted too precisely. But that’s your province, I suppose. You and our friends from Special Branch, anyway. I expect they’ll have their own ideas.’

Kessen didn’t look pleased at the mention of Special Branch.

‘How long would it take somebody to attach a device like that to the vehicle?’