The silverback, heavy on his knuckles, now crabbed sideways into a thicker patch of vegetation, which partly obscured him for a moment. I lifted my camera to my eye. Beside me Caleb took a step forward. ‘We’ve got to do something about that injured baby, you’re right,’ he said to Amelia.

‘No, no, no,’ insisted Innocent. ‘Stay still.’

The bushes into which the silverback had retreated rattled and staccato guttural alarm calls came from within them.

‘It’ll die if we don’t intervene,’ Caleb went on. ‘Look at it. Poor thing.’

The injured baby gorilla, still limp over its mother’s arm, wasn’t moving. Of course I felt sorry for it. And for its parents too. But if we could have helped, Innocent would have said so. He was saying the opposite. Squatting next to Patience, I saw that the tendons in her father’s neck were rigid with tension. If he’d had a leash on Caleb he’d be drawing it in now. But there was no leash, and Caleb, shirtsleeves rolled and swinging that stupid machete of his, Caleb who I sincerely doubted would lose a moment’s sleep over the baby gorilla, however things turned out, Caleb was taking yet another step towards the troop.

‘Really?’ muttered Xander. ‘I mean, what’s he trying to prove?’

It wasn’t just what he was trying to prove that struck me in that moment, but who he was trying to prove it to.

Within the undergrowth concealing the silverback, the top of a large sapling bent sharply. A splitting, ripping sound accompanied the movement. The gorilla had torn down a tree three times his height. He rushed forward again, dragging it, and flung it aside without apparent effort, scattering some of the troop, most of whom were now noisy, restless, agitated. The silverback beat his chest again, veered off in a different direction, spun and faced us.

I could feel my pulse in my throat, hear my heart despite the din.

‘Just showing off,’ said Caleb.

‘Perhaps we should give him some space,’ said Xander.

‘Oui. Lentement, lentement …’ urged Marcel, smoothly stepping backwards.

‘What’s wrong with you?’ said Caleb. ‘The worst thing you can do in a situation like this is run away.’

Nobody was running. Quite the opposite. But having accused us of doing so, Caleb, looking straight at the silverback across the clearing, for some reason felt compelled to take two big strides towards him. He drew himself tall, pointed at the gorilla with his machete, and said, ‘See? Harmless.’