Police captain Matveev is not the first time he has solved a series of heinous murders. The capture of another maniac leads him to the idea of the existence of some single evil, insatiably thirsting for new monstrous crimes. His investigation and hypothesis lead to a mysterious monastery located high in the mountains, far from civilization. Several mysterious murders take place here. Matveev investigates them. He meets two Buddhist monk pilgrims: the elderly Chen and his young companion Mao, who arrived, as it turned out later, on a secret mission. Matveev learns from the Chinese about an ancient secret - the existence of the curse of the master Wang Lan, whose fate is forever connected with the dark forces of evil.