Now that he pointed it out it seemed obvious, but I’d liked Detective Hubert and didn’t want to think he was somehow in my uncle’s thrall. ‘Langdon’s cancelled his plans to be here helping,’ I said lamely. ‘Maybe he’s giving the police the detail now.’

‘You think?’ said Amelia.

‘Langdon says there’s no problem,’ said Xander. ‘Your mum and dad will turn up eventually, he thinks, and that’s that. Somehow he got Detective Hubert to agree.’

I’d taken the policeman’s agreement as a positive thing, but according to my friends I was deluded. I felt my hackles rising even as I saw the sense of what they were saying.

‘We all want them simply to show up,’ said Xander. ‘Of course we do. But there has to be more we can do than just hanging around here, waiting.’ He reached towards the cheeseburgers but took the fork from beside the nearest plate instead of the burger on it, jammed the fork’s handle down the inside of his plaster cast, and wiggled it about.

‘Nice,’ said Amelia.

‘My shin is so itchy,’ he explained.

‘Scratching itches makes them worse.’

‘You’re wrong about one thing at least,’ he said, scratching harder. To me he went on, ‘If we could piece together their movements before they left, find out who they met with and what they talked about, we might come up with a lead. As I understand, it they were pitting themselves against some pretty powerful people who – I hate to say it, but there’s no point in pretending – might well have had good reason to want them out of the picture. Do you know the detail of this summit they’re attending in the run-up to the vote?’

‘Not really.’

Amelia said, ‘It’s called the Inaugural DRC Conference on Sustainable Development, and basically it’s an opportunity for environmental activists from around the world to persuade the Congolese government to regulate mining in and around the national parks. A lot of unscrupulous businesses, not to mention armed militia, want the opposite. There’s a big vote on a bit of legislation called Article 16B, which sets out what’s allowed and what’s not, coming up in thirteen days’ time, and the summit is an attempt to influence the outcome.’

‘Where does she get the detail from?’ Xander asked me.

‘Here and there,’ I said.

‘Actually, with this I googled it while we were in the police station,’ said Amelia.

‘Why?’

‘Because the one thing we know for sure is that Nicholas and Janine will want to be here to witness that vote. They’d also like to be around to meet with officials, ministers, businessmen et cetera in the run-up period, but knowing when the actual vote is happening gives us their absolute deadline: that’s when they have to be back.’