The examining magistrate Hopek goes to a lonely manor house to settle a property matter with the lord of the manor. When he arrives, he learns that the lord of the manor has died of a heart attack during the night. Although everything suggests that the lord died of natural causes, the strange behavior of the lord's family and servants arouses the suspicion of the examining magistrate, and he begins to investigate. The very first results strengthen his doubts. He finally succeeds in unmasking the landowner's son. The film is based on a short novella by Witold Gombrowicz, who was awarded the International Literature Prize in 1967.