Shadow of the Moon by M M Kaye
M. M. Kaye, author of The Far Pavilions, sweeps her readers back to the vast, glittering, sunbaked continent of India. Shadow of the Moon is the story of Winter de Ballesteros, a beautiful English heiress who has come to India to be married. It is also the tale of Captain Alex Randall, her escort and protector, who knows that Winter's husband to be has become a debauched wreck of a man.
When India bursts into flaming hatreds and bitter bloodshed during the dark days of the Mutiny, Alex and Winter are thrown unwillingly together in the brutal and urgent struggle for survival.