Kiel, just before the opening of the Kiel Week. Everything is preparing for the event of the year. Now, of all times, inspectors Borowski and Brandt are dealing with a particularly puzzling murder case. A young woman who has been insidiously murdered is found in an empty apartment. There is no trace of the perpetrator, who had set himself up at the scene of the crime as if in hiding. When another corpse turns up a little later, it becomes clear that the apparently unscrupulous perpetrator will stop at nothing to return to the anonymity of theto be able to submerge the city. Borowski and Brandt are alarmed: Are they dealing with a serial killer or is the perpetrator covering up an even more perfidious plan? The largest folk festival in the north is now in full swing and this arouses an increasingly outrageous suspicion.
Under the pressure of events, the tensions in the investigative team are increasing. While Sarah Brandt wants to put the perpetrator on the hunt and thinks about warning the public, Borowski urges prudence.