The life of King Béla IV's daughter is brought to life in the film. Blessed Margaret of the House of Árpád was raised from the age of nine in the monastery of the Domokos nuns on the island of Nyulak. In the neighbouring monastery live monks, among them Jancsi, the gardener's son, who is charmed by the little princess. The feeling of love gives him the cross and the adolescent boy becomes a monk among the "prisoners of God".