‘You tried to destroy my career with your little online stunt yesterday,’ Stacey says. ‘You’ve been digging around in my past trying to find more dirt to use against me. Your son told me that, by the way. Gave me all the details. He’s very loyal. Just not to you.’ She opens the window a couple of centimetres, letting in a sharp blast of cold air. ‘Please pass my best on to your husband, too, won’t you? He did a nice job wiping my computer.’

We’re getting closer to London now: the trees have given way to streetlamps and unlovely buildings, and I’m forced to slow as the traffic snarls.

‘Look,’ I say, keeping my temper on a tight leash. ‘I told you before: we can both still walk away from this. Whatever’s going on with you and Felix, I want no part of it. I just want to be back in my OR where my only concern is keeping my patient alive. What I don’t want,’ I add sourly, ‘is to be hijacked in my own car. What I don’t want is to be looking over my shoulder every five minutes, or wondering if my son is going to slide a knife between my ribs on your behalf while I sleep.’

‘OK,’ Stacey says.

‘OK?’

‘A truce. That’s what you want, right? You go your way, I’ll go mine?’

‘Yes,’ I say warily. ‘I’d be happy if I never saw you or your damn house again.’

‘Fine,’ she says. ‘A truce. But it comes with strings attached, Millie.’

‘Yes,’ I say. ‘I thought it might.’

chapter 58

millie

Sunday is a difficult day. I spend most of it watching my son as he guzzles Cheerios, milk dripping down his chin, or lies on his stomach playing with his Lego, wondering what my tousle-haired, clear-eyed, freckle-faced boy is really thinking. The question isn’t whether he crept out of the house after he’d been sent to bed and walked half a mile in the dark to Stacey’s: I already know he’s capable of that. His invasion of our neighbour’s house a few weeks ago wasn’t an isolated incident: he was far too slick and confident for it to be a first time offence. He sneaks around in the dark, listening in corners and watching from the shadows. Disappearing in the night to the Glass House would have been – literally – child’s play.

The real question is why.