When he was satisfied that they had gone, he went forward again, stepping carefully through the litter. As he drew closer to the bodies he saw that Hugh had been crudely emasculated and that Helen’s breasts had been cut off. The vultures had enlarged the wounds. The jaws of both corpses had been wedged wide apart with wooden pegs. Leon stopped when he reached them and stared down at them. ‘Why are their mouths prised open?’ he asked, in Kiswahili, as his sergeant came up beside him.

‘They drowned them,’ Manyoro answered quietly, in the same language. Leon saw then that the clay beneath their heads was stained where some spilled liquid had dried. Then he noticed that their nostrils had been plugged with balls of clay – they must have been forced to draw their last breaths through their mouths.

‘Drowned?’ Leon shook his head in incomprehension. Then, suddenly, he became aware of the sharp ammonia stink of urine. ‘No!’

‘Yes,’ said Manyoro. ‘It is one of the things the Nandi do to their enemies. They piss in their open mouths until they drown. The Nandi are not men, they are baboons.’ His contempt and tribal enmity were undisguised.

‘I would like to find those who did this,’ Leon muttered, disgust giving way to anger.

‘I will find them. They have not gone far.’

Leon looked away from the sickening butchery to the heights of the escarpment that stood a thousand feet above them. He lifted his slouch hat and wiped the sweat from his brow with the back of the hand that held the Webley service revolver. With a visible effort he brought his emotions under control, then looked down again.

‘First we must bury these people,’ he told Manyoro. ‘We cannot leave them for the birds.’

Cautiously they searched the buildings and found them deserted, with signs that the government staff had fled at the first hint of trouble. Then Leon sent Manyoro and three askari to search the banana plantation thoroughly and to secure the outside perimeter of the boma.