‘It was very good,’ I say. ‘Very articulate. You presented yourself well. It was all bullshit, of course, but I’m sure it went down a storm.’

‘They want me to do a series for one of the streamers,’ he says, leaning back. ‘I’m the poster child for rehabilitation, apparently. I’ve been asked to take part in research studies at Cambridge and Yale. Everyone wants to know what makes me tick.’

‘Inside the mind of a psychopath,’ I say.

He laughs. ‘You’ve got to admit, it’s a catchy title. Everyone loves a psycho. You’re all just fascinated by us, aren’t you?’

‘I’m sure the parole board will be impressed.’

‘My lawyer says I’ve got a good chance at the hearing next month,’ Peter says. ‘Will you be there? He says it makes a big difference if the victim’s relatives support the application.’

Nine years ago, I protected my son and let Stacey Porter take the blame for Felix and Harper’s deaths. I kept silent about what I’d seen, what I knew. I persuaded Tom to delete an eerily prescient vlog Harper had made that incriminated Peter. And for five years he rewarded me by being the perfect child. He played for his school’s football team. He volunteered for charity fun runs. He worked out at the gym. He had a girlfriend. Even Tom believed Peter had turned a corner. We fed the good wolf, and the good wolf was winning.

And then one day, a day just like any other, our fifteen-year-old son came home from school and slit his father’s throat.

‘Do you ever wish you’d chosen differently?’ Peter asks suddenly. ‘Do you ever wish you’d saved your hand that day in the cellar, instead of me?’

It’s a question I’ve asked myself a thousand times over the last four years. If I’d let Peter die in that freezer, Tom would still be alive. Afterwards, if I’d done as Tom asked and told the truth, the whole truth, I would still have my husband.

Instead, I watched Peter get taller and broader and fitter and stronger, until he was strong enough to kill the man I loved.

There was no reason, because psychopaths don’t need a reason. He did it because he could. He saw it as perfectly reasonable: the young lion ousting the old for the good of the pack. His expensive legal team blamed it on the pills he’d been taking from someone he’d met at the gym, some version of ‘roid rage’. They pleaded the charges against him down to manslaughter, and he was sentenced to just eight years at a low-security facility, a prison with rose gardens and rowing machines and flatscreen TVs. But he and I both know what Peter did had nothing to do with pills.