Walter Fane, a reserved British bacteriologist, marries Kitty Garstin, a frivolous socialite. They move to Shanghai, but their marriage becomes strained when Kitty has an affair with a charming diplomat, Charlie Townsend.
Upon discovering her infidelity, Walter forces Kitty to accompany him to a remote Chinese village ravaged by a cholera outbreak. Initially resentful, Kitty begins to see Walter in a new light as she witnesses his compassion and dedication to helping the villagers.
Gradually, Kitty matures and finds purpose in assisting nuns who care for orphans. The bond between her and Walter strengthens, leading her to fall genuinely in love with him—not out of duty, but out of newfound respect and sincere affection.
Tragedy strikes when Walter contracts cholera and dies. Pregnant with his child, Kitty returns to England, transformed by her experiences. She resolves to live independently, no longer the shallow socialite she once was.