The story is set in 1925. Kitty (NAOMI WATTS) is a spoiled young woman living in London. Facing the social stigma of her younger sister getting engaged first, Kitty quickly marries one of her suitors, Walter (EDWARD NORTON), a boring bacteriologist.
The couple moves to Shanghai where Walter researches ways to control epidemics in Asia. Although Walter is madly in love with Kitty, he finds that the pair has little in common and discovers that Kitty has an adulterous affair with a married diplomat, Charles (LIEV SCHREIBER - Naomi's real-life boyfriend). In order to teach his wife a lesson, he volunteers to work in a remote Chinese village where the plague is raging and local warlords are waging battles. Walter threatens Kitty to divorce her stating her infidelity if she does not accompany him to the area. She accepts the offer in order not to spoil her reputation and she feels disappointed when she knows that Charles will not ask for a divorce from his wife.
Living in the village where more and more people die of cholera, Kitty begins to appreciate his husband who gives no regard to his own life for the good of others. She also starts working in an orphanage to help the unfortunate. The hazardous journey indeed brings Walter and Kitty closer. Unfortunately fate intervenes…
Special thanks to the Intercontinental Film Distributors (HK) Ltd.