The historical story of František Vláčil takes place in the harsh realities of the second half of the 13th century. It depicts the conflict between the forced affiliation to the ascetic crusader order and the desire for a free life. The fanatical knight Armin von Heide (Jan Kačer) chases his friend Ondřej (Petr Čepek), a descendant of a Czech peasant family who fled and returns to his native fortress. The knight is determined to punish him for violating the rules of the order and during Ondřej's wedding night he breaks into his bride's bedroom.