In the tranquil Kinzigtal, four women's bodies are found in different locations, but no one knows who the deceased are. All victims were killed in the same manner, and the perpetrator has tied either a white or a black scarf around them. Criminal Director Dr. Christoph Caspari is faced with a mystery. Is he on the trail of a serial killer? While he and his team do everything they can to stop the series of murders, unknown individuals are sabotaging the investigation. And what begins as a hunt for a psychopath ends with a threat to their own lives.