‘I’ve tried to be kind,’ Stacey says. ‘To let you down gently. I told the police: this is as much my fault as yours. I led you to expect too much. I let it go too far. I never thought you’d take it out on Felix.’

‘Video can be incriminating,’ I say. ‘A picture’s worth a thousand words. It’s easy to see how someone might get the wrong idea even when there’s an innocent explanation. If there was a video of a woman punching and hitting her husband for example,’ I add. ‘A husband who’d then gone missing in suspicious circumstances. Well, it’d be easy to see how the police might jump to conclusions.’

It’s Stacey’s turn to pause. ‘Hidden cameras,’ she says.

‘I didn’t need to hide a camera,’ I say. ‘Just download a virus to Felix’s computer, which gave me access to the camera. Though when I checked it last night, the content turned out to be a bit unexpected, I must admit.’

‘It’s not what it looks like,’ she says.

‘But what it looks like is all that matters,’ I say.

The silence stretches between us. ‘So,’ she says.

‘So,’ I say.

Stacey drops her hands, letting her towel fall to the carpet. Her breasts are white and full, her belly soft. She puts her hands on my shoulders, and lifts her mouth to mine. For a long moment we drink each other’s breath.

Adrenaline and desire flood my system, a high like nothing I’ve ever experienced: not running the roofs of train carriages in the dark, or free-climbing a cliff in Yellowstone National Park, or making love to my husband, or holding a human heart in my hand. It’s the danger she poses. The risk. Every nerve in my body is on fire. I don’t think I’ve ever felt this alive.

But I don’t forget what Stacey Porter is capable of, not for one second.

These violent delights have violent ends, and in their triumph die, like fire and powder, which as they kiss consume.

Shakespeare knew a thing or two about love.

She sees my answer in my eyes. Her hands drop to her sides.

‘It’s not too late to row back from this,’ I say. ‘You could tell the police Felix had a nosebleed. All the evidence they have against me is circumstantial. I’ll make sure you’re safe. We can both still walk away.’

For a moment, I actually think she’s going to agree. Honour satisfied on both sides. A hard-fought draw against a worthy opponent: perhaps we’ll even stay friends. She has my respect, which is a commodity I parse out even more carefully than friendship. We could be quite the team.

‘Ahh,’ she says, tilting her head to one side with a regretful smile. ‘If only my memory was just a little more reliable.’