They stood close together on the station platform in the fog of early morning, laughing and crying, hugging the nuns and teachers whom they had never once embraced during all their years in school classrooms, promising to keep in touch, to write letters, to visit one another soon. Hannah had come to the station to say goodbye and she stood beside Camilla, making bad jokes, hiding self-conscious sadness. Sarah moved away, unable to mask her tears. Part of her life was already over and she felt dislocated, heading into an empty space without guidelines or familiar faces. The Indian stationmaster appeared on the platform. His breath vaporised in the frosty air as he broke up farewells and directed the chattering, tearful girls into the carriages. He slammed doors, shouted orders at the train driver, the engineers and the sleeping-car attendants. The girls hung out of the windows, waving and calling out their very last goodbyes as the train pulled out of the highland station, trailing a mournful whistle as it carried them away from their childhood years.

As they shunted into Nairobi in the late afternoon, groups of parents were standing on the platform, faces beaming with anticipation. There were shouts of welcome as children and their luggage were deposited on to the platform. Porters wheeled school trunks away to waiting cars. Sarah tried to guess which of the crowd was Marina Broughton-Smith.

‘Saidi, jambo. Our luggage is over there.’ Camilla addressed a young man in a chauffeur’s uniform. ‘This is my friend Memsahib Sarah who has come to stay with us.’

‘Where are your parents?’ Sarah knew instinctively that she should not have asked, but the words came out before she had time to consider their implications.

‘God knows. They’re busy, I suppose. We’ll get to them all too soon.’

Saidi drove them through the broad streets of the city to the residential area of Muthaiga, where tree-lined avenues bordered acres of manicured lawns and flower beds. There was a cold formality about the Broughton-Smith house that was immediately disturbing, and the silence unnerved Sarah as she stepped across the threshold. She felt that it was a place without a soul, an impressive pile of stone bearing no resemblance to home as she knew it. There was no sign of Camilla’s parents as she followed the houseboy upstairs to the guest wing. Her room had a canopied bed, a velvet sofa and matching armchair, and her own bathroom. It was impressive and too large, and it felt lonely. She thought it must look like an expensive hotel suite, although she had never seen one. Outside, a huge expanse of lawn was framed by shrubs and a rose garden. When she opened the window the air was cool, and sweet with the scent of flowers.