When her chronically unemployed husband runs off to start a crocodile farm in Kenya with his mistress, Josephine Cortes is left in an unhappy state of affairs.

The mother of two—confident, beautiful teenage Hortense and shy, babyish Zoe—is forced to maintain a stable family life while making ends meet on her meager salary as a medieval history scholar.

Meanwhile, Josephine’s charismatic sister Iris seems to have it all—a wealthy husband, gorgeous looks, and a tres chic Paris address—but she dreams of bringing meaning back into her life.

When Iris charms a famous publisher into offering her a lucrative deal for a twelfth-century romance, she offers her sister a deal of her own: Josephine will write the novel and pocket all the proceeds, but the book will be published under Iris’s name. All is well—that is, until the book becomes the literary sensation of the season.