Detective Hubert did too. ‘We’ll do everything we can,’ he told us all. ‘I’ll initiate our missing-persons protocol. As soon as I have any news, however small, I’ll be in touch.’ He handed me a card with his contact details written on it in a startlingly green font. ‘And you do the same for me, OK?’

The phrase missing-persons protocol sounded so official. My gaze fell to the floor as he said them. I fought back the fear, tried to put some steel in my voice and failed. ‘Sounds a fair deal,’ I whispered.

31.

Langdon ran us back to the hotel. En route he made it clear that he’d intended to fly east with Caleb that morning but would be staying in Kinshasa to help deal with what he called ‘the situation’. He said he was pleased I’d persuaded him to go to the police. It felt like he was on my side, genuinely trying to be helpful: there was no hint that he resented the inconvenience of my absent parents, but I still felt the need to apologise on their behalf for mucking up his schedule.

He waved the apology away. ‘I’ve got bags of things to be getting on with here,’ he said. ‘And anyway, it’ll be good for Caleb to make a start without me breathing down his neck.’

‘Thanks,’ I said, meaning it.

‘That’s OK. You have my number. Use it if you need to. I know it’ll be tough waiting here, but try not to worry. Think how much they’ll owe you when they show up again!’

With that he was off, leaving us on the steps of the luxury hotel I’d grown to hate more than boarding school. At least the days pass quickly there. That afternoon and evening in the hotel dragged by tortuously slowly. We were all up at daybreak, and after a morning spent failing to think of anything constructive to say to one another Amelia announced that she was going to cool off in the pool. She proceeded to swim lengths very quickly for a long time, which I happen to know is her way of venting her frustration. I sat with Xander, who pretended to read a book. He’s normally so laid back that some of it rubs off on me, but perhaps because his leg was hurting, he was in no mood to talk. I gnawed on the inside of my lower lip until it bled, trying to make myself believe in what Langdon and Detective Hubert had insisted, that Mum and Dad would stroll through the lobby doors any moment, or at least that the phone on my lap would light up with one of their numbers, but of course neither of those things happened. I could not will away my fears.