He nods. ‘You’re right. We can’t ignore the possibility. We’ll get her photo over to forensics and ask them to check it against Mason’s images. ‘Meanwhile, see if you can find anything, May. Names of investors or any photographs of Hollie … Anything.’

In the dim light of Mason’s cellar, even the air seems laden with darkness as I search for any evidence.

‘Hard to believe that no-one would have known what was going on here. Look at these.’ The DI passes me a handful of photos of naked and semi-naked girls.

It’s a measure of how depraved so many people are that what might have shocked, even a few years ago, has become normalised, acceptable. But it’s how the human brain works, and with mounting human desire for the ever more shocking, there is a growing market for acts of escalating obscenity. And for as long as there’s a demand, there will always be Masons.

But to use children and young girls is to cross an unacceptable line. As I look at the photos of girls of a variety of ages and nationalities, I find their exposed bodies distressing enough, but far worse are the expressions in their eyes. Some are obviously drugged – oblivious – while others are simply terrified. Unable to take any more, I go outside.

Leaning against the wall, I glance at Sarah. ‘Hampton deserves everything that’s coming to him,’ I tell her. ‘As for Mason …’ I shake my head, failing to find the right words.

‘Even in our job,’ she says slowly. ‘You think you’ve seen it all, but there’s always a lowlife who manages to surprise you. Doesn’t say much for the human race, does it?’

I shake my head. There are many good people in the world, but at times like this, it’s easy to believe that they are outweighed a thousandfold by the bad. ‘We just have to make sure we get him.’ Mason – and everyone else involved. To let them carry on with what they’re doing is inconceivable.

Chapter Thirty-Four

Elise

After work, I see a missed call from DI May, but when I call her back it goes to voicemail yet again.

But I don’t have time to worry about it. By the end of the day, having viewed a small cottage on the outskirts of Tangmere, I’ve managed to fast-track the usual rental process by paying a deposit and putting down three months’ rent in advance. It feels like a momentous step, even though it’s the easiest part of my plan. What will follow is going to be much harder.