1939: Europe is on the brink of war when young Lily Shepherd boards an ocean liner in England, bound for Australia. She is ready to start anew, leaving behind the shadows in her past. The passage proves magical, complete with live music, cocktails, and fancy-dress balls. With stops at exotic locations along the way -- Naples, Cairo, Ceylon -- the voyage shows Lily places she'd only ever dreamed of and enables her to make friends with those above her social station, people who would not ordinarily mingle with her. She even allows herself to hope that a man she couldn't possibly have a relationship with outside the cocoon of the ship might return her feelings. But Lily soon realizes that she's not the only one hiding secrets. Her newfound friends -- the toxic wealthy couple Eliza and Max, Cambridge graduate Edward, Jewish refugee Maria, fascist George -- are also running away from their pasts. As the glamour of the voyage fades, the stage is set for something sinister to occur. By the time the ship docks, two passengers are dead, war has been declared, and Lily's life will be changed irrevocably.