None of us says anything else for a while. The atmosphere is heavy. Subdued. And I wonder if Carrie or me did something embarrassing – something that the others know about but we don’t. I have no idea how we got home, so I suspect someone must’ve helped us. But I don’t want to ask any questions. I don’t want them to think that I have no idea of what happened in the last few hours. I realise that I don’t even have any concept of how long a period of time is missing from my memory.

The Land Rover bumps hard across the dusty steppe roads, and it’s all I can do to take small sips of water from the bottle that Martin gave me when I sat down. Rory and Carrie are asleep, which I think is miraculous under the conditions – but sometimes sleep overrides everything.

‘It’s been quite an adventure,’ Martin says to me, at last. ‘I’m glad we met up with you two. Shame we’re going in different directions now.’

We were always going in different directions, but I don’t tell him that.

‘Any tips for Beijing?’

I can see the high-rises of UB on the horizon. We’re still trundling across the harsh earth, barely a thing around us except for sparse grass and the outlines of the mountains far away on either side. ‘Well, it’s got a lot more people in it than this place.’

‘Nine million bicycles,’ he says.

‘At least. Oh, that’s a song isn’t it?’

He starts singing, and he’s not bad. Shame we didn’t get to go to karaoke. ‘Is the smog as bad as they say?’ he asks.

‘Worse. You think you can see it but you can’t, really. It just looks like thick, grey skies. But you can feel it. You can taste it. It squeezes your head like a vice. And there’s so much noise, and colour and everything is just…’

‘Frenetic?’

I nod. ‘Yes, frenetic. I’ll tell you where I went for a bit of quiet time – weirdly. There’s a shopping mall under the Hyatt with a food court, with loads of brilliant food. It’s called the Oriental Plaza. Amazingly, it’s not really a tourist kind of place, and you can just eat and chill and no one will bother you in there.’

‘Sounds great.’ He twists around in his seat to face me. ‘Anything else?’