A second picture is placed alongside the first. Now I can make out two figures against a low wall, their torsos crushed together. They might be lovers if you cared to interpret it that way, but I know they are fighting. Fighting over a woman, fighting for their lives, though neither knows it yet.

Only one face is visible to the camera.

‘Can you identify either of these figures, Mr Buckby?’

Again, Evan attempts to interrupt the questioning and, again, I dismiss him. I touch my own face in the photo with a tentative finger. ‘This looks like me, but if it is then the time must be faked. Like I say, I was at home then. Clare will confirm that.’

The detective ignores this, making a comment for the purposes of the recording that I have identified myself in the evidence. ‘And the other person?’

‘I have no idea.’

‘You don’t remember who you were with?’

‘The date’s faked, so if I don’t know when it was taken, then I don’t know who I was with.’ I cling to my line: everything is faked now, it’s an established problem for seekers of the truth.

But the police are seekers of convictions, which is not necessarily the same thing.

‘Do you recognize the location, Mr Buckby?’

‘No idea,’ I repeat. The blackspot is out of range of all cameras and we were alone, which means Melia must have taken this photo, careful not to use flash, as the detective points out. I would have noticed that and so would Kit.

Witch. Double-crosser. Right in front of our eyes – except our eyes were on each other.

I pick up my water beaker, but it’s empty. I chew at the rim, as if that will yield liquid. ‘Could I have some more water, please?’

Evan slides his cup towards me and I pour the remaining liquid down my throat. I say thank you but do not meet his eye.

‘We believe the second figure is your friend, Mr Roper,’ the detective says.

‘It could be,’ I agree, ‘just not any time recently. As I keep explaining, I haven’t seen him since Monday the twenty-third of December. I thought he’d been reported missing and I wasn’t the only one to think that. For God’s sake, Merchison and Parry detained me for half the morning on that basis!’

‘Ah, yes, the famous Merchison and Parry.’ An audible lungful of breath, followed by a theatrical sigh, tells me what he thinks of the allusion. ‘You were interviewed under caution, were you?’

‘No. It was only an informal chat.’

He chuckles. ‘An informal chat that took up half the morning. Right.’

‘Yes, right. Someone needs to investigate them. If they’re not in the Met, then they should be charged with impersonating a police officer. That’s an offence, isn’t it?’ I’ve said this several times to police staff since being arrested, but it’s clear that all, including this one, the one who counts, think I’m making my inquisitors up, that they’re phantoms, delusions. Names plucked from some magazine ad or a label on a box that caught my eye in the café as I spoke to the uniformed officers: Merchison & Parry, purveyors of traditional gingerbread. My face floods as I remember Sarah Miller, soprano. Merchison must have seen her name on a poster or a flyer in the RFH, then doodled it in his pad, making himself look like a real detective, noticing things. What else was in that pad? A shopping list? Ideas for anniversary gifts for his wife? Does he even have a wife? A spike of fury pierces the deadweight of self-pity in me and I feel my face flame.

‘Let’s leave that issue for now and return to the photograph, if we may. Is it possible that this could have been taken on the stretch of the river where Mr Roper’s body was found earlier today?’

‘I wouldn’t know which stretch that was,’ I say, teeth gritted.

‘I thought you said your partner told you? It might interest you to know that we’re checking all CCTV footage from cameras in St Mary’s on New Year’s Eve, including the roads between your house and the river.’

I feign a shrug. There’ll be nothing on the main route, I’m confident of that much, but any amateur could find the alternative access path with a cursory google and my precautions strike me now as utterly woeful. Melia assured me it was clear of security cameras and because I had no reason to doubt her my own reconnaissance was far from exhaustive. Might there have been a distant camera I wasn’t aware of, somewhere beyond the gates of the St Mary’s Wharf construction site? A camera she alone knew to evade?

A bulb flickers overhead – or maybe I’m imagining it. ‘This timestamp has been faked,’ I repeat, blinking.

The detective’s gaze does not waver. ‘We’ve tested its authenticity and we’re satisfied it meets evidential requirements.’

Otherwise, they might not have had enough to arrest me. And I don’t need my new friend Evan to take me aside and explain it is likely going to be enough to bring a charge all on its own.

I have a memory of myself in Rosie’s Café, haranguing Melia. Have you heard from him? Is he still AWOL? Lines rehearsed to show concern for a missing person, but might they just as easily have been those of a man hunting another man with the intent of doing him harm? My face that afternoon was crazy-eyed. I’d looked deranged.

Just as I know I do now.

‘It was Melia,’ I say, abruptly. ‘She took this photo. She’s set me up.’

As my solicitor tries more strenuously than ever to intervene, to somehow negate this last catastrophic offering, I raise a hand, insist I know what I’m saying. The detective lowers his shoulders, adjusts his gaze. He was not expecting a confession so quickly, but then this is not my first interview, no matter what he prefers to think.

‘You mean, you were with Mr Roper at one forty-three on the morning of January the first?’

‘Yes. We were by the river in St Mary’s. Just along from the Hope and Anchor.’

He taps the photo. ‘And this is him in the photograph with the person you’ve already identified as yourself?’

‘Yes.’ I take a breath and expel the truth: ‘But I didn’t stab him. I admit I’m guilty of not reporting a crime or whatever that’s called, but not murder. She did it.’ When he makes no immediate reply, I raise my voice: ‘Look at me, surely you’re trained to tell if someone’s telling the truth!’

His mouth tightens, as if to warn me that more challenging individuals than me have sat in this spot and spat out their lies, their avowals and confessions. ‘To be clear, when you say “She did it”, you’re talking about . . . ?’

‘Melia, of course! I just said!’

‘Melia Roper, Christopher Roper’s wife?’

That’s the moment when I see my future – hear it. The way he says her name, the incontrovertible rejection in his tone. That’s when I know beyond a shadow of a doubt she is not sitting somewhere else in this building being subjected to a parallel interrogation, but is at home being comforted and cared for. Elodie is going to turn out to be a special-needs teacher or a social worker and she will swear on the lives of our city’s vulnerable or her own babies that Melia was in the flat with her all night, a unit so compact she couldn’t have failed to notice her friend’s absence (unless she was drugged, of course). Clare, meanwhile, will freely explain we weren’t sharing a room; we weren’t even on the same storey of our big rich-person’s house. I could have been doing anything while she slept, a bottle of wine in her system.