Uppsala, 1907. In the Swedish province, a wealthy bourgeois family celebrates Christmas in Grandma Helena's home. Among the numerous members of Ekdahl, there are two children, Fanny and Alexander, sons of the local theater director, Oskar. It is through their visionary gaze that we can observe the whole affair. Shortly after the festivities, Emilie, the young mother of the two children, remains a widow for her husband's sudden death. After a few months he ends up marrying Bishop Vergérus. For Fanny and especially for Alexander, the world changes to become a nightmare with open eyes. Abandoned the toys and the warmth of the childhood home, will have to adapt to the rigid canonical life and the austere house near the Cathedral. Between tragic events that occurred before their arrival and the disturbing presence of the bishop's sisters, for Emilie and her children life becomes oppressive. Reality and imagination mix and only thanks to the magical intervention of Isak Jacobi, a Jewish antiquarian and family friend, the two children can hope to save themselves from the clutches of their stepfather.