In the darkened sky, the street lamps flicker orange. I see a boy in the distance under a lamp that reminds me of Amit. His face glows in the sulphur.

I turn round and push at the door to a desk sergeant I haven’t seen before. This one looks more awake and less irritable than the others have been.

‘Is DI Blake here?’

He looks at his screen, takes my name and picks up a phone. ‘Yes, Rachel. Someone here to see you.’

I put the bag on my lap and look at it. It has kept my life’s secret. When I think of Grace and Rory, they are all in the centre of my life, whether I orbited around them or they me. But – and this hasn’t penetrated me until now – they are gone. They are dead and the damage that I did to them still clings to me. I have been running, but I haven’t been able to free myself from their guilt or their blame because I have kept them with me. How could I run away from them when they are inside me?

But now, I can escape. Knowing this, I look up.

‘Xander,’ she says. ‘Twice in twenty-four hours?’

I stare at Blake and at the bag on my lap. This moment feels suspended between two outcomes.

‘I have this,’ I say, and show her the muddy bag. She looks at me, confused. ‘It’s the other bit. Of the record. I had it,’ I say.

She is walking towards me but stops abruptly mid-stride and draws in a breath. ‘Xander. I. Oh, shit. I need to caution you,’ she says, putting a hand on her head and then sitting softly next to me. I can smell a faint scent of coffee and jasmine.

‘I’m seizing this as evidence in the case,’ she says at last. ‘Wait here. I’m going to get an evidence bag and some gloves.’ She rushes off through the double doors and is gone no longer than a minute or so. When she returns she has a large polythene bag in her hand and is pulling on surgical gloves. She takes my bag and seals it in the larger one. When she has written on the label, she turns to me.

‘I can’t ask you any questions about this without cautioning you and then interviewing you with your solicitor,’ she says, levelling her eyes at me. She is signalling.

I nod and then get up to leave.

‘Xander. You know we’re going to test it, don’t you?’

‘Yes,’ I say, and walk to the front door, pausing to raise a hand at her in goodbye.

‘I can’t not follow the evidence, Xander,’ she calls to my back as I walk out.