‘That’s kind of her,’ Tom says sarcastically.

‘She is kind.’

A beat falls.

I take an apple from the fruit bowl, and cut it in half. I’m in no mood to let Tom off easily. ‘If you think Stacey’s so dangerous, why were you so happy to leave our son with her?’

‘I didn’t say she was dangerous. Don’t put words in my mouth, Millie. But if I was a betting man, I’d put my money on Peter anyway.’

The words hang in the air. It’s the first time Tom has come close to acknowledging the truth about our son aloud, and the relief of it rolls through me like a wave.

I’ve barely let Peter out of my sight since Sunday. But in less than two weeks, the school term starts again. The teachers can’t watch all the kids all the time. There’ll be plenty of opportunities for a boy like Peter. Bunsen burners left unattended. Children walking to school along busy main roads.

Tom refuses to meet my eye. He has an oddly hangdog air.

And then suddenly it hits me.

He knows.

He knows what our son is, but he’s let me carry the burden on my own because he’s been too much of a coward to acknowledge the truth.

For years I’ve watched the darkness growing inside our son while Tom’s buried his head in the sand, cutting me off at every turn: it was an accident, Millie. He didn’t mean to. He’s just a kid.

How dare he question my judgement when he’s spent so long wilfully suspending his?

‘Felix is playing you,’ I say abruptly. ‘You believe him because he looks and sounds like you. But I’m telling you, Tom, he’s the bad guy in this scenario.’ I slice the apple with quick, angry strokes. ‘And I’m going to prove it.’

chapter 36

millie

The malware I introduced into Felix’s laptop when I was in his office isn’t particularly sophisticated, but it works. A tech expert like Tom would spot the Trojan horse in a nanosecond: there’s a slight but perceptible delay when webpages load and a small icon in the corner of the screen that’s a dead giveaway.

But Felix isn’t looking for it. He’s clearly far too preoccupied: he’s spent the weekend scrolling through a variety of stock market indices and updates, opening multiple windows on his desktop and shuttling back and forth between them. Thanks to the virus I uploaded, I’ve been able to watch his every move on my own computer.

I close my laptop and run upstairs to find Meddie. ‘I’m just going out for a run,’ I say, putting my head around her bedroom door. ‘You all right on your own for a couple of hours?’

She pulls one of her AirPods out. ‘Where’s The Freak?’