Set in 19th century China, the novel centers around the lifelong friendship of Lily and Snow Flower. Despite their different social classes, the two communicate through a secret language known as "nu shu" written on a fan. The story explores the rigid societal norms of the time, particularly the practice of foot binding and arranged marriages. As they navigate through the hardships of their lives, their friendship is tested, leading to a devastating betrayal that impacts their relationship.