‘This is Sergeant Luke Hardy,’ Suzanne said, introducing the first man. ‘He’s leading the armed response unit. And this is Sergeant Tony Fraser, our negotiator.’

That was where he knew the pudgy man from. Fraser had become a minor celebrity for a few days last year when he had successfully negotiated with a man who had taken his estranged wife and their three children hostage. The husband had, famously, exchanged one of the children for two packs of cigarettes, before eventually giving himself up.

The hostage negotiator’s job was basically to keep Koppler talking and engaged so that the rest of the team could work out how to get the hostages out of there. ‘Have you already talked to him?’ Patrick asked.

Fraser nodded. ‘He’s demanding safe passage for himself and his family, as he calls them.’

‘Or?’

‘His exact words were, “If we can’t live together as a family, we’ll die together as a family. I’ve got a gun. I’ll do it, you know.” ’

‘Shit.’ He looked back at the house, just in time to see a curtain fall back in one of the upstairs bedroom windows of number 20, catching a glimpse of a figure that might or might not have been Koppler. The house was red brick, lovely, the garden well-kept, a thrush hopping about on the lawn. The sun was shining. The headlines, if this were all to go wrong, wrote themselves: Horror in Suburbia.

‘It’s not going to go wrong,’ he said under his breath.

‘At the moment, Koppler is refusing to talk anymore. He won’t answer his phone.’ Fraser paused. ‘We’re listening in to the phones of both Koppler and Fredericks—’

‘You’ve established she’s definitely in there?’ Patrick interrupted, glossing over the legality of what Fraser had just said. It was strictly illegal to hack into anyone’s phones without written permission from the Home Secretary, as Fraser would well know. But this was a life and death situation, and it was unlikely he’d had time.

‘Yes. Koppler named her when I first spoke to him. But they’ve both been quiet. No calls to or from their mobiles or the landline, no texts. If you’ll excuse me, I’m going to try to call them both again, hope one of them answers.’

Suzanne said, ‘OK, let’s debrief.’

She looked tired, Patrick thought. Tense. She was the ranking officer here, and Patrick knew she would be in constant contact with ACPO. If they fucked up, if Koppler was able to go ahead with his threats, she would be the one who took the flack. It made him even more determined to get those kids out of there safely.