In the small regional center of Ozerka, several brutal serial murders occur. The maniac chooses only girls as victims. Traces of torture and abuse confuse even seasoned operas: the killer burns the body of each victim with a hot fork, leaving a kind of “mark of the devil” on the skin. Local journalist Lina Zhuravleva, who writes on criminal topics, is trying to break through to Major Parfenov, the senior officer of the operational group. But the police have a persistent hostility towards the journalist; they ignore her on principle and do not want to listen to her. The girl has no choice but to bare her back in front of the major. To his horror, Parfenov sees a burn in the form of four stripes - exactly the same as those on the girls killed by the maniac. And Lina tells the major a terrible family secret, how as a child her parents bullied her and tortured her with a hot fork. Does this mean that the maniac is known?! But the story turned out to be worse and more mysterious. Under strange circumstances, Lina's parents burned alive in their own house many years ago...