Before I met Melia.

There’s a booking-in process that takes an age and gives me time to recover from my absconsion, my confusion in the tunnel. To clarify my situation to myself, understand my rights. ‘Have you arrested anyone else, as well?’ I ask the custody officer, but am told to worry about myself and leave police work to the professionals.

Eventually, I’m introduced to the duty solicitor and taken to a room far removed from the large interrogation chambers you see on TV, where officers get buzzed in and out and chief inspectors watch through a one-way mirror as suspects pace like caged tigers. This is small and oppressive and could be a unit at a job centre or a parking office: we sit on rough-textured plastic seats at a smeared table, on which there is digital equipment of some sort. A wall-mounted camera in the corner with an all-seeing eye. There’s no offer of coffee, but I am permitted a plastic beaker of water.

The solicitor sits by my side. Evan, a good Welsh name, even if his accent is pure home counties. I try to bring to mind our pre-interview conference – he was briefing himself as we spoke and there was some grumble about disclosure. He is about my age and wears his world-weariness in extra kilos around his waist. Once or twice he yawns and I smell cigarettes on his breath, which makes me think of Kit and me on the stoop, looking out over Prospect Square.

How the hell do you get to live in a place like this?

He thought I had it all and didn’t deserve it, when in fact I was busy preparing for exactly what I deserved: nothing.

A detective comes in. A real one. I don’t absorb his name, but he is so totally unlike Merchison and Parry I could weep at my stupidity. It’s not just his appearance – unremarkable, mid-priced suit, complexion that speaks of long-term dietary compromise – but also his sour odour of institution, of overwork. He is in his early forties and has rounded, boyish features, with a bright, obliging manner that feels hackneyed, as if he’s signalling to me that he is not to be surprised, I am no one he hasn’t sat face to face with a thousand times before.

He says he is recording our interview and activates the equipment, checking that I can clearly see what he is doing. The time and place are stated, as well as the names of all present. When asked to give my address, I have a profound sense that I will never set foot in Prospect Square again. I am the outcast now, the dispossessed.

‘Okay, Mr Buckby.’ He insists on eye contact before beginning. ‘Perhaps you’d like to start by telling me why you took it upon yourself to take off the way you did this afternoon when our officers spoke to you at your place of work?’

‘Because I thought . . .’ My voice is a mumble and I clear my throat, raise the volume to a more confident level. ‘I thought I must have been framed for Kit’s murder and I got scared. I’m sorry. It was a crazy thing to do, I didn’t mean to waste your time and budget.’

He gives me a sarcastic Well, that’s all right then kind of look and I understand that what little benefit of the doubt I might have been entitled to, I’ve squandered. He is entirely disinclined to believe a word I say.

‘What made you think he’d been murdered? You hadn’t been told that by our officers, had you?’

‘No, but my partner had phoned earlier and said she thought it was a stabbing.’

‘Did she now? Her job is what?’

‘She’s in property. What I mean is, she was in the area and she overheard someone say it was a stabbing. She didn’t see the body with her own eyes.’

The body. I can’t connect with what I’ve done, what Melia has done. It’s evening by now and the river bus commuters will be arriving home. Are the police still there, rainwater dripping from the tent, cordons in place?

‘Right. Well, what I’m interested in, if we’re going to get anywhere tonight, is what you’ve seen with your own eyes. Okay?’

‘Yes.’

‘Where were you on Tuesday night of this week?’

‘At home.’ I repeat the answers I gave the uniformed officers in the café. Again, Clare is invoked. If I’ve established anything in the time between arrest and now, it’s that this is Melia’s word against mine, whether she is questioned as a suspect or as the victim’s family or both. I have Clare to alibi me and she has Elodie. Surely someone as successful and respectable as Clare will be more convincing than Elodie? I try to remember her profession, if I was ever told it. Most of the Ropers’ friends are ‘creative’, so if there’s any justice in the world, Elodie will be flitting between casual jobs, constantly demonstrating her unreliability. An uneasy voice corrects mine: Melia will not have picked her at random. I shudder.

Bright eyes grip mine once more, demand my focus. ‘Let’s look at the period between midnight and six in the morning on Wednesday, Mr Buckby.’

That must be the time of death. ‘I was in bed. I sent some New Year’s messages to my family, then I listened to a radio drama. I slept from about one to eight-thirty in the morning.’

‘What radio drama was it?’

‘Just an old Jeeves and Wooster thing.’

‘In a lighthearted mood, were you?’

‘Not really, it was just good to fall asleep to.’

‘Because you were keyed up about something?’

‘No, not at all. But I could hear fireworks going off, a bit of party noise from the square outside. I just wanted to relax. I’m sure you could check my phone, or search history or whatever.’

‘I’m sure we could. What was the Jeeves and Wooster story? Fill me in.’

His style is relentless: this is no game of cat and mouse, but the lightening of an unmanageable workload with optimum efficiency. I’m of no fascination to him, only an arrogant chancer who believes his life is worth more than other people’s and who has been wicked enough to act on that belief.

I wouldn’t have a hope even if I did disagree with him.

‘I can’t remember,’ I say, truthfully.

‘Try. Give me some idea of the story.’

I strain for a likely detail. ‘I think it was the one where he helps his friend break off his engagement.’

‘Sounds like an episode of Friends.’ There’s a pause, a moment of amusement shared with Evan rather than me, a split-second of security I’d be a fool to put my faith in. ‘Thank you, Jamie, that sounds very complete. A nice, civilized early night. The problem is, we’ve got this.’

It is a photograph, in black and white. As I peer at it, tilting my head to rid the surface of the glare, discussion ensues between the two of them about disclosure. Evidently, the item should have been submitted to us before the interview. Evan suggests a break, a private conference, but I wave away the idea. ‘It doesn’t matter whether I saw it before or not, because I can’t tell what it is.’

This is true. There is little discernible variation in the dark tones of the image. But then I see the timestamp in the corner – 01/01/20 01.43 – and I brace in my seat. The atmosphere in the room heightens and quickens and contracts. Everything slams into everything else.

My interrogator resumes: ‘This is an image sent anonymously through our witness appeal channels. It’s been taken without a flash, so you’re right, you can’t see anything much, but if you look at this enhanced version our techies have sorted out for us . . .’