Leningrad, 1967. A series of murders takes place in the Obvodny Canal area in the very center of the city. The maniac operates exclusively at night: he rapes and strangles women, leaving mysterious signs over the bodies of his victims - strange symbols drawn with charcoal. KGB Major Chubin, who already has experience in solving similar cases, is involved in the investigation: several years ago he tried to expose a pagan sect that worshiped Chernobog. Then the major attempted to infiltrate the secret society, but was discovered, and he himself became a victim of the cruel psychopath who led the sect. Chubin was saved at the last moment, but the experience left an indelible mark on the man's fate. Despite the psychological trauma he has suffered, Chubin remains a professional in his field. He is the only one who specializes in solving serial murders, and immediately understands that the current series is again connected with the cult of Chernobog.
