Abruptly and mercifully, just when I thought I could take it no longer, Innocent stopped. In his lilting whisper he explained, ‘Where we are, and the direction the poachers are going, they must also sleep out tonight. They’ll make camp while they have light. Good progress. Tough boys.’ Here he clenched his fist. ‘I think we’ll catch up soon. So quietly now: let’s not run into their camp by accident.’

We moved on more slowly. The whooping, chattering hum of the jungle intensified around me as I tried to make less noise myself. In fact we had to endure another half-hour of this creeping progress before Innocent stopped again, and by this time the light was already failing. High above us, the canopy had turned a purplish black and all the green beneath it was grey. He motioned for us crouch lower, stay still and keep silent. We did, but it was hard; the mosquitoes, which had dogged us all day as we moved, clouded around us more thickly when we didn’t. For many long minutes we sat there in the glowering dampness, waiting. I wondered whether Innocent had mistakenly stopped us too soon. Then the purple gloom deepened, and as night established itself I spotted the yellow dot of a flame in the darkness ahead. It danced and grew, a camp fire taking hold.

‘That’s them?’ I asked, my voice a whisper above the whining mosquitoes.

Innocent nodded. He took out his GPS and tapped its screen. Very quietly he explained, ‘We know where they stopped us and we know now where they camp. Draw a line between two coordinates and extend it: we can predict where they head for tomorrow. Et voilà, rangers can intercept.’

Caleb looked pleased with himself. ‘What did I tell you,’ he said.

‘Yes, that’s the first part done. But now we must retreat as far as possible before making our own bed for the night.’ Innocent’s face was grim. ‘No picnic.’

I turned from the distant firelight. The jungle we had to retreat through was now a dense black web. Beside me, cockiness gone, Caleb drew a nervous breath.

‘Hand on my shoulder, and his on yours,’ Innocent told him. We did as we were told, making a little human chain behind the guide. How he could see the way I’ve no idea. We didn’t rush, that’s for sure: at a glacial pace, step by step, doing everything we could to stay concealed, we inched away.

18.

When I was eleven I caught chickenpox. That’s quite late to have it: everyone assumed I was already immune. I only got a few scabs, they didn’t itch that badly, and aside from one spot high on my forehead they didn’t scar. But for three days I had a blisteringly high temperature. I became delirious. At its worst I was convinced that my bedsheets, knotted about me, were an octopus’s tentacles. Mum put a fan next to my bed: the sound of it was wave-roar. Apparently I started shouting all sorts of nonsense about drowning. That’s because I thought I was! It was terrifying.