When Alice Verinder's beloved sister Lydia goes missing, Alice boards the Orient Express bound for Topkapi Palace in Constantinople, determined to find her. Lydia was governess to the Sultan's young children and though her letters spoke of exotic delights and welcoming hosts, the reception Alice receives is decidedly cold and answers unforthcoming. Now, as Alice digs deeper into the secrets of a land foreign to her she has only Englishman Harry Frome to help her. But as their search uncovers unforeseen dangers and exposes an unexpected ardour, is Alice ready for the truths they'll uncover?