‘Of course I mind, Bryon. But I imagine you, being you, scared the living daylights out of him.’ I contemplate the Forum, its soapy white neo-classical columns, its shallow steps and elegant black street furniture and at its centre – an aching absence where its central monument should be. Already I am finding it difficult to remember what the horse and rider looked like. Now that my eyes have registered their absence, the statue is being scrubbed from my memory, washed away as swiftly as a dream.

Loophole’s development team, swimming in all the money and resources Vaux has thrown at it, has hit a serious snag. Now Vaux wants to see if I can spot it on my own.

‘Hang on.’ I study the gap where the monument once stood. ‘I think I see it.’

A family of tourists – mum, dad, two children with backpacks – are making their way in front of the arch on the south-eastern corner of the square. As they pass behind the absent column, they stutter and vanish. A second family appears, identical to the first. Mum, Dad and the kids walk across the road, clear the statue’s occlusion fan, and disappear, one by one. Another identical family appears, several yards in front of the group that’s just vanished. Christ. The glitch. The fault.

‘That took you about eight minutes.’ Vaux smiles. With silvered lenses in his eyes, the expression is predatory. ‘Not bad.’

Vaux has another meeting. I leave him at the mouth of the metro, and walk alone through the Ministries, trying to clear my head.

One by one we are transforming the spaces we have cleared. Here, for example, the ministry buildings have been replaced by paint-blue ponds where no birds swim. Lawns. Forests. We have entirely levelled a square mile south-west of the forum, filling the gap with potato fields that our great-grandparents’ generation would recognise. Hedgerows bend and sway.

Walking through this rusticated city, the air tastes fresher, though of course I know it’s just as muggy and polluted as always. With grass under my feet – albeit imaginary grass – I have become attuned to subtle gradients. I’ve learned to navigate, less by what I see, but more by the lie of the land under my feet. I can picture in my mind’s eye the organic shapes into which the city has been plugged, and which, after so many centuries, it has still not altogether erased. Little by little, and in unexpected ways, we are rubbing the city away to reveal the pattern of a forgotten land.

The mind juggles maps very poorly. Now that I am growing used to our clarified and minimal city – city as park, as field, as bucolic blank, like something out of one of Michel’s later, gentler post-apocalypse tales – I am finding it harder and harder to navigate the city as it really is. The truth is, I don’t like going out without my lenses now. An unaugmented walk through the stews of the city, hemmed in by its buildings, assaulted by its aniline palette, my concentration shattered by all its overlapping signage, leaves me feeling increasingly uncomfortable. My heart chatters. My breaths grow short and painful. I need a break.

I need a friend.

Airport security have to let us disembark eventually, and Gabby is at the gate to meet me. ‘Looking good,’ she smiles. She hefts the bags off my trolley. She wants to show me she’s still got her strength.

We climb into a cab.

The altitude here is serious; even in the city centre, there is still snow on the ground. Crowds in expensive coats gather around stalls selling mulled wine and buttered rum. We pull up before the cathedral. Gabby’s apartment is high up in a retail and hotel complex nearby. ‘Bloody hell, Gabby, what does this cost you?’

‘Nothing. I hacked their booking server.’

‘What will you do when they find out?’

‘Sleep under the desk at work. Busk outside the Cathedral.’

I can’t be entirely sure that this is a joke. The apartment is well-appointed, perfect for bringing home women of a certain age – the divorced, the curious, the incorrigible – and ideally suited to ejecting them again in the morning.

‘Do you want to freshen up? I’ve booked us a table for nine.’

The apartment has a wet room. A shower that wraps you up in a warmly scented tropical rain. Towels as big as blankets. Coming out, I find Gabby watching an international news channel. She lifts her hand to grasp mine. ‘Good to see you, Connie.’

‘And you.’

‘You look tired.’

‘I look how I feel.’

‘Are you up for tonight? Just dinner. Friends. We don’t have to stay out late.’

‘Of course.’

I slump opposite her in an upholstered chair.

‘I dug up what you asked me for about Bryon Vaux. But if you’re speaking to him—’

‘He spoke to me. Michel told him about me and he put two and two together.’

‘So you’ve talked.’

‘Only about work. I haven’t asked him anything – important.’

Gabby shoots me a look. She thinks I’m being obscure for the sake of it. That I’m leading her on. She’s remembering our childhood games with Dad’s tin soldiers; my endlessly changing rules of engagement. ‘Look,’ I say. ‘Tell me what you found. And I’ll explain.’

‘You promise?’

‘Yes.’

‘Okay. For a start – and you could have found this out from any celebrity site – Vaux was not a serviceman.’

This draws me up. ‘What?’

‘Vaux wasn’t in the services. He wasn’t a soldier. Everyone assumes he’s a veteran. He was a journalist. Embedded. Good at it, too. It’s why the grunts like him. Factually, his films have always been on the button.’

‘Now I’m completely at sea. I thought he was a soldier.’

‘People do. He plays up to it.’

‘But his eyes. He’s seen action.’

‘Of course he’s seen action. He was embedded on the front line. He took a laser in the face.’

‘But what was a writer doing among a bunch of army men, getting a vest fitted by my Dad?’

Gabby turns her hands palms up as though to say, where’s the problem? ‘A battlefield injury, a military hospital, and from there a referral. Wouldn’t it make perfect sense, treating Vaux alongside others blinded in the field?’

‘Did you find out why he discharged himself from the hotel?’

‘Plenty of your dad’s guests did.’

‘Really?’

‘It wasn’t strictly a clinic. Some took to the vests, some didn’t.’

‘And did Vaux?’

‘Christ. How am I supposed to find that out?’

‘I think maybe Dad would have made a record.’

‘Well, I can keep looking.’

‘Please.’

‘Now. Are you going to tell me what the fuck this is about?’

I take a breath. Another. (The air here is really very thin.) I am going to have to give her something.

In the end it’s Gabby who buys me time. ‘You can tell me as we go. Come on. We’ll walk. It’s a nice night.’

She leads me, slipping and sliding (‘I told you to bring boots’) through the city’s pedestrianised centre, from stall to stall, knocking back punch and spiced wine by way of an aperitif. With alcohol inside her, she is a little more forthcoming about what she has discovered. ‘The records have Vaux down as twenty-seven when he got his eyes burned out.’

‘How long was he at the hotel?’

‘A couple of months.’

‘Gabby.’ No way round this. ‘Do you remember – did he have much to do with my mum, do you reckon?’

Gabby is ordering us mugs of rum. She leans against the bar. ‘Oh, Conrad,’ she sighs, her gaze sliding away from mine to lose itself in the rings and smears on the bartop. ‘Who knows what your mum got up to?’

‘But you heard something. You know something. Did your mum tell you something? Did Frankie know something?’

She hands me my mug. ‘Are you finally going to tell me what this is about?’

‘I think Bryon Vaux was the last man to see my mum alive.’

‘Oh.’ Gabby sips her rum. Again. ‘I see.’ She sips. ‘Well. Fuck.’

‘Now, if you can tell me how to broach that particular subject with Bryon Vaux, without landing myself in a world of pain, I’d like to hear it.’