Count George Vilbois, descendant of an old French family that emigrated to Poland, is a young, wealthy, and righteous man. However, he is burdened by heredity, and his normal state, at the stroke of twelve at midnight, fades, and the impeccable man... transforms into an apache with all the instincts of a primitive man... He commits criminal acts, of which he knows nothing when he returns to consciousness. On one such nocturnal expedition, he murdered a street girl, Stasia, whom he took up because she bore a strange resemblance to his fiancée, Lila Korska. A few years after their wedding, the unfortunate man's condition deteriorated significantly... and George began to live by day, even as he had once lived only by night. This drew the attention of police agent Maks, whose lover the murdered Stasia was, and who ultimately proved that Count Vilbois was the apache who murdered her. The film has not survived to this day.