Detective Vseslav Smirnov was approached by businessman Rudnev with a seemingly trivial matter - someone was intimidating his mother over the phone. But soon the elderly woman dies... It turns out that there have already been several similar cases, reminiscent of poisoning by an unknown poison. Vseslav travels to the town of Berezin, where Rudnev’s mother lived in her youth. There the detective finds out that the girl turned to the healer when her fiancé abandoned her. After this, the guy died, and the healer, according to rumors, turned into a dog and ran away into the forest... During the investigation, Vseslav understands that an ancient cult is involved in this story. His priestesses actively used poisons, which were kept in a golden casket with an image of a dog on the lid. And Smirnov guessed what to look for...