East of the Sun by Julia Gregson
My rating: 3 of 5 stars
Summary: Autumn 1928. The Kaiser-i-Hind is en route to Bombay. In Cabin D38, Viva Hollowat, an inexperienced chaperone, is worried she's made a terrible mistake. Her advert in The Lady has resulted in three unsettling charges to be escorted to India.
Rose, a beautiful, dangerously naive English girl, is about to be married to the cavalry officer she has met only a handful of times.
Victoria, the bridesmaid, is determined to lose her virginity on the journey before finding a husband of her own in India. And overshadowing all three of them, the malevolent presence of Guy Glover, a strange and disturbed schoolboy.