A runner is killed at Lake Rusalka in Poznan. Anka, a journalist from a small town, decides to take up the case. He goes to Poznan to keep up to date with all the findings of the investigation. He accidentally contacts a policewoman, Lidka, who has a theory about the crime, but her voice is downplayed at the police station. Rusalka's case quickly turns out to be not only investigative material, but also a strong trigger of social, women's agitation. How does the myth of the Slavic demon come to life in the modern world? Can murders have noble motives? Or are they a sign of the decline of modern society?
—G