The main guard had taken a couple of steps backwards. Now the others followed suit, the noose of their circle relaxing.

‘Take names,’ Caleb was telling Francis. ‘Tell them my father will be pleased to hear of their vigilance. Explain that we’ve undertaken this visit on his behalf. They’ll be rewarded.’

Francis began relaying all this before Caleb finished saying it, and Marcel somehow got himself between the guards and the three of us while the translation was going on, shepherding us away up the hill with an insistent, ‘Suivez-moi!’

We did as we were told and backed away further up the slope. I kept my eyes on the guard with the rifle. Mesmerised by those fidgety fingers, I wasn’t exactly focusing on where I was stepping, and I lost my footing on the uneven ground and sat down in a pool of sludge. The guards all looked my way when this happened and mercifully found it funny. I slapped my forehead, very clown-like, which made one of them laugh out loud. This gave Francis the opportunity to disentangle himself from the conversation.

‘Physical comedy is weird like that,’ Amelia said, helping me up. ‘I’ve no idea why, but it defuses tension.’

‘Deliberate ploy,’ I said.

‘Really?’ she asked, looking impressed.

I didn’t tell her the truth.

54.

Covered in muck, I led the way out of the mine the way we had come, picked up the steep path and quickened our pace despite the gradient, desperate to get out of there. When it became clear that nobody was following, my heart rate dropped by about a third; I hadn’t realised it was beating so fast until it slowed. In the wake of panic, a hollow ache spread across my chest. Mum and Dad would be proud of the evidence I’d managed to photograph, but the trip had drawn a blank as far as actually finding them was concerned. Caleb, who’d fallen into step beside me, seemed to know what I was thinking.

‘There are other mines, other contacts. This was just the first – what the …?’

I followed his gaze, up the track to where the 4 x 4 was parked, and did a double take of my own. Where there had been one Land Cruiser, now there were two. Both were painted in the same white-on-green livery of Langdon’s mining company. The second had clearly just arrived, its exhaust still pumping out diesel fumes. Both Caleb and I stopped walking. Marcel and Francis and Amelia caught up with us. Francis saw why we’d stopped and gasped.