The canopy above us thinned out a little from time to time, but the undergrowth, one or two welcome clearings aside, was pretty unrelenting. Innocent and Marcel – and Caleb of course – increasingly had to use their machetes to cut us a pathway through it. The noise of the rainforest was unending, a constant drone-hum of insects punctured by rain-hiss and leaf-patter and the whooping and chattering of birds, monkeys, god-knows-what, overlain with our own hard breathing and the squelch of our boots and the snick of the machetes: it was music, of sorts, a soundtrack encouraging us to keep on walking. And that’s what we did. We were all puffing harder than Patience, but managing to maintain a pace that I think impressed our guides all the same. Innocent paused less often than he had en route to the chimpanzees. We took on water (I’d made sure to bring three times as much with me that day) without slowing down. It was tough going, but either the troop had moved closer or we made better progress than Innocent had predicted. After just two and half hours Marcel, who had been making the occasional soft grunting noise as we walked, heard something in response that made him kink left, push through some dripping ferns and kneel down next to a hefty pile of greeny-yellow droppings. ‘Juste là-bas,’ he whispered.

Innocent handed out masks before allowing us to get closer, and not long after we’d begun moving forward again I glimpsed a tantalising hillock of black fur through the foliage. Moving stealthily, we emerged at the edge of a trampled clearing of sorts. I crouched low and quickly counted six, no, seven gorillas. The nearest one was stripping leaves from a long bent stalk. I was close enough to see the fibres in the stalk as she broke it, the shifting black of her fur and the tiny flies that rose in a cloud as she turned. Her eyes were a reddish brown. The creases around them looked like the laughter or worry lines you see in a human face. Immediately I realised I was doing the one thing we’d been told not to do, stare straight at her, but I couldn’t help it. Her gaze was magnetic. It was all I could do to break from it and look to one side. Even then the imprint of what I’d seen didn’t fade. To me the gorilla had the look of an elder, a judge, a prophet even; she seemed not only to know what I was thinking, but to be deciding it.