It is the end of the nineteenth century and China is riding on the crest of great change, but for nine-year-old Willow, the only child of a destitute family in the small southern town of Chin-kiang, nothing ever seems to change. Until the day she meets Pearl, the eldest daughter of a zealous American missionary.

Pearl is head-strong, independent and fiercely intelligent, and will grow up to be Pearl S Buck, the Pulitzer- and Nobel Prize-winning writer and humanitarian activist, but for now all Willow knows is that she has never met anyone like her in all her life. From the start the two are thick as thieves, but when the Boxer Rebellion rocks the nation, Pearl's family is forced to leave China to flee religious persecution. As the twentieth century unfolds in all its turmoil, through right-wing military coups and Mao's Red Revolution, through bad marriages and broken dreams, the two girls cling to their lifelong friendship across the sea.