When young, beautiful Kitty Garstin finds herself in a bind after turning down too many suitors for too many years, she marries Walter Fane unthinkingly, without love. They move to a British outpost in China where he works as a doctor; there, bored and lonely, she strays into a two-year affair that is eventually discovered. Rather than divorcing her, Walter decides they will both travel to a cholera-stricken town for his work. The discoveries Kitty makes and the challenges she faces in this deadly place change her world and open her eyes to the terrifying and beautiful reality of life.