The driver was always available to take them into the centre of Nairobi where Camilla seemed to spend much of her time. They would find a pavement table in the Thorn Tree Café, where they ordered iced coffee topped with ice cream. Camilla knew everyone, and she appeared to be interested in all aspects of their lives, enquiring about children and grandchildren, siblings and lovers, golf handicaps and bridge scores.

‘How do you remember all these people’s friends and relations, and their various peccadillos?’ Sarah asked.

‘Everyone has a story, you know. Even some dreary old man with yellow teeth and a frayed bush jacket will have something amazing to tell. I’ve learned by watching Father. He does it all the time in his job, and he’s very good at it. And it means I’ve always got someone to talk to.’

The words were such a stark admission of loneliness that Sarah turned away to hide an unwelcome feeling of pity. The idea that these passers-by were a substitute family for Camilla flashed into her mind, but she dismissed the thought as being foolish and far-fetched.

‘But you never tell them anything about yourself,’ she said as Camilla lit another cigarette.

‘They all know my glamorous parents, and they think I’m bound to be just like them.’ Camilla was watching the safari cars being loaded with tin trunks, expensive leather suitcases, and wooden boxes containing guns and ammunition. ‘Look at those mountains of luggage – what are they going to do with it all, in the middle of nowhere?’ she said.

‘God, I’d love to be rich and going off to my own tented camp. White hunter, craggy looks, big rifle, lions roaring in the night.’

‘Primitive and sweaty. But I can see you right there in the thick of it. When Piet starts up his game reserve you can go with him.’ Camilla saw the flicker of pain as Sarah looked away. ‘Oh, for heaven’s sake, Sarah. I’ve said I’m sorry dozens of times.’

Sarah hesitated, wanting to comment but reluctant to let the misery resurface during her Nairobi stay. She sat there in silence, watching as Camilla projected a dazzling smile at someone, looking up through the beat of long eyelashes.

‘Anthony. Are you off on safari?’

‘I’m going out with one of the Ker and Downey hunters as a back-up. Four clients, with three shooting. One looks a little shaky this morning. I think he sank a bottle of Scotch last night in the Long Bar. We’ll be gone for about a month. Coming with me?’

‘God, no. I have no interest in sharing some swampy safari camp with a bunch of strangers.’

‘I’m not a stranger. There’s room in my tent.’

‘Don’t be ridiculous, Anthony.’ Camilla was laughing. ‘This is my friend Sarah Mackay. Anthony Chapman.’