They drive in silence, Sophie staring out of the passenger-side window, Josie and Sandra in the back.

Sophie turns to Robin. ‘I want to go in there,’ she says. ‘I can persuade him to come out, I know I can.’

Robin glances her way as he negotiates a roundabout. His anger has subsided, and tiredness and hunger are starting to take over.

He sighs. ‘It’s not as simple as that, Sophie. He’s not in his right mind. You don’t know what you’re going to face if you go in there.’

‘He’d never do anything to hurt me.’

‘I would have said he’d never do anything to hurt anyone, but here we are: Finn locked in a van with a dead body. There’s blood everywhere,’ he says quietly, trying to keep the women in the back from hearing this fact, one Craig had held off from telling them earlier.

‘There’s blood?’ Sophie says, her face draining of colour.

Robin nods. ‘And I’m guessing you’ve never seen a dead body before, right? Let alone one that’s been murdered?’ Sophie looks like she’s going to be sick. ‘It’s a messy crime scene, Sophie. It’s not like it’ll just be you and Finn having a cosy chat.’

She shakes her head. ‘I can’t believe Finn killed him.’

‘Nor can I,’ Robin says quietly.

Sophie goes back to staring out of the window.

As he drives, Robin thinks about the van. What would he do, if he was in charge of the case? He glances at the time. It’s one p.m. now, and Finn’s been in there with a dead body for at least seven hours. With no food, on little sleep. Robin knows there’s no way they’ll let it get to nightfall.

The longer it goes on, the worse it’s going to be. Robin knows Craig will be trying to get eyes into the van so they can see what’s going on. He knows she will be trying to talk to Finn. Keeping lines of communication open in a negotiation means the offender might let you into what they are thinking. And then be persuaded into leaving peacefully. An offender. He’s still struggling to see Finn in that way.

In the past, they’ve called a dog unit. He’s had people lock themselves in buildings, and the mere threat of a large toothy Alsatian being sent in has been enough to get the most hardened skinhead out with their hands in the air. But not with Finn. Not with him in this state.

Professional detachment has helped him this far, but in the face of what they’ve seen in the flat, he is scared for his friend.