I remember Clare telling me last night that she’d had missed calls from her too, though no voicemail had been left. Should she call her back, Clare had asked, her reluctance clear.

Leave it, I told her.

I blink, aware of the detectives’ scrutiny as I dither; they’re surely noticing my bandage, changed this morning but already grubby. I select the contact for Regan, who will by now have dealt with the deliveries of milk, sour-dough and pastries and be grinding her first coffee orders. It’s her habit to get in half an hour early, make herself a premium-grade matcha and open up solo. Her flat share sounds like hostel conditions and those thirty minutes before I arrive are the only ones she’ll get all day to spend in a room alone.

Going to be late, sorry. I stare at the screen as if an answer will come at once, something to rescue me, but of course she won’t have time to look at her phone. By eight thirty, the queue is out the door.

‘All done?’ DC Parry asks with an edge, like I’m taking the piss. Clearly he’s less accommodating than his partner and the moment I put the phone down, he gets down to business: ‘So, according to Mrs Roper, her husband failed to arrive home on Monday night and you were the last person to see him . . .’

There’s a significant pause where the word alive should fall.

I answer politely. ‘You mean on the boat home? To be fair, Melia wasn’t with us to know who that was.’

But this pedantry is water off a duck’s back. ‘Members of the crew witnessed you both disembarking and we’ve also spoken to another passenger who saw you alone together. Mrs Roper has spent the last few days contacting family and friends and is certain no one else has seen him since then.’

‘I’ve had missed calls from her myself,’ I concede. ‘I haven’t had a chance to get back to her.’ I wonder about this other passenger. Obviously not Gretchen, since I’ve just seen her and she made no mention of having been contacted by the police. Steve, perhaps? The last person besides Kit that I remember noticing, he got off at North Greenwich fifteen minutes before us. He’s off work now till next week, but I’m fairly sure he would have phoned or texted me if the police had been in touch.

I remain composed. ‘I suppose you’ve already checked the security video on the boat?’

‘We have indeed. So, your recollection of Monday night . . . ?’ Parry prompts.

‘We got the last boat home together, that’s right. A few of us got on at Blackfriars after Christmas drinks at Henry’s on Carter Lane.’

‘The others being?’

‘Gretchen Miles and Steve Callister. We’ve got to know each other on the commute, had drinks a few times. We always sit together.’

The names don’t appear to be new to them, though Merchison jots an extra note I can’t decipher. Both detectives have big A4 pads in front of them, but only he has produced a pen.

‘But it wasn’t that late when we got to St Mary’s – the last boat gets in at eleven thirty. Someone else must have seen Kit after that, surely?’

‘That’s what we’re trying to discover,’ Parry says, frowning. I can tell he’s finding me unusually sanguine about a friend having been reported missing. ‘Did you and Mr Roper pass anyone in the street on your way up from the pier?’

‘Not anyone I particularly remember. We didn’t walk together, actually, so he may have.’

His gaze sharpens. ‘You didn’t walk together, even though you live a few streets away from each other?’

‘No. Normally we do, but . . . Come on, you obviously saw from the video that we got into a bit of an a row on the boat? I marched off ahead. I didn’t want to spend another minute with him.’ The statement hangs between us, I can almost hear it spinning around a wood-panelled courtroom – I didn’t want to spend another minute with him – and I’m not surprised by the doubtful look they exchange.

‘What was this row about?’ Merchison asks.

I sigh. My throat feels painful and gritty. ‘Nothing much. We were both the worse for wear. But I didn’t want to hang around arguing. I had a very early start in the morning, a train to catch from King’s Cross, and, like I say, I assumed he followed.’

‘Are you and Mr Roper in the habit of arguing?’ Parry says. Unlike his colleague, who shifts constantly in his seat, he has the sharp-eyed stillness of an owl.

‘No, not at all. We’re mates. We were drunk, that’s all.’ Without thinking, I bring my bandaged hand to my face and of course he makes the association I’d prefer he didn’t.

‘Injure yourself in this fight with your mate, did you?’

‘No. This is a burn from the coffee machine at work. Speaking of which, is there any chance we can get some coffee?’ My first, a double espresso at home, has worn off. Usually by this time I’d be at work and firing up my second or, if I’m lucky, being handed one on arrival by Regan. ‘Look, there must be security cameras between the pier and the high street, so why don’t you check them and you’ll see it was exactly as I’m telling you?’

I happen to know that the route back to Prospect Square took me past at least one other CCTV camera. ‘Maybe ask at the bar on Royal Way? Mariners, it’s called, on the corner of Artillery Passage, less than two minutes from where the boat docks. We often go there after getting off the late boat, so maybe he went on his own this time.’ I pause, convincing myself. ‘Yeah, I bet he stopped for a drink there, met someone and, you know, continued his evening.’

Merchison’s pen scratches the paper throughout this speech and when he raises his gaze I see a flare of interest in his eyes. ‘Are you saying you think he spent the night with someone other than his wife?’

‘Maybe. If he didn’t go home, then I’d say it’s a possibility.’

‘Is several nights a possibility? Thewhole Christmas break?’

Both detectives’ scepticism is plain to see. I shrug. ‘Look, I’m not saying he’s eloped bigamously, just that he might have carried on partying and got caught up in something and now he’s sleeping it off. I mean, he must have been somewhere these last few days, mustn’t he? He’s not some loner, he’s a very social animal.’

Once, in the summer a few weeks before the wedding, Kit and I stayed out all night. It was a Friday and we’d got off the boat at North Greenwich, found a club near the O2 that stayed open till dawn. I remember there was a charity walk starting at midnight and it was surreal to watch thousands of women in leggings swarm by all bright-eyed, before limping back six hours later in a miasma of exhaustion. Melia, staying with a girlfriend across town, was not around to disapprove, but Clare was spitting blood when I finally skulked home at 8 a.m. ‘He’s young, Jamie, he can take it physically, but you might have a stroke!’ And for the rest of the day my inbox pinged with links to articles about middle-aged men falling down dead after binge-drinking.

I don’t say any of this to the police. Instead, I look from one detective to the other, spreading my integrity evenly between them. ‘Seriously, any minute now, he’s going to come strolling back in, probably not even sorry he wasted your time. So I should probably go to work now – my colleague will be struggling on her own. Plus it’s not the kind of job where you get paid if you’re not there, you know?’