Johanna Wokalek, John Goodman, and David Wenham star in director Sönke Wortmann's adaptation of author Donna Woolfolk Cross' novel about a woman who dared to live like no other woman in history, and found herself at the center of a treacherous political conspiracy. The daughter of a 9th Century European priest, Johanna (Wokalek) defies dogmatic doctrine by learning to read and write. Later, after Johanna's secret gets out, she receives special permission to parochial school in Dorstadt.The only female in the school, she is placed in the care of Gerold (David Wenham), a brave knight with whom she falls deeply in love. But their romance is shattered when the Normans attack, prompting Johanna to assume the persona of a man and take flight to a Fulda monastery. Ordained in the practice of healing, Johanna later becomes the private doctor of Pope Sergius (Goodman) in Rome. Her fate takes an extraordinary turn, however, when Bishop Anastasius poisons Pope Sergius in an attempt to claim his title, and Johanna ascends to the throne instead. Though at first no one suspects that the new pope is in fact a female, Johanna's secret soon threatens to become known after she discovers that she is pregnant with Gerold's child.