There is a state of emergency shortly before the Kiel Week. Three million guests from all over the world are expected to celebrate the largest summer festival in Northern Europe. Now, of all times, a treacherously murdered woman is found in an empty apartment in the middle of the city center. There is no trace of the perpetrator, who had evidently set himself up in hiding for months. When inspector Borowski looks around the victim's apartment, he suddenly finds himself in front of a wall of fire. Roman Eggers and the inspector face each other for a moment. Eggers tries desperately to annihilate the consequences of his crime - and saves Borowski at the last moment. Then he disappears into the anonymity of the city, which is slowly filling up with people. When another body is found, Borowski and Brandt are alarmed: Are they dealing with a serial killer?

Borowski's last case led to the transfer of his colleague Sarah Brandt. In order to escape the anger in the commissariat, Borowski plunges into a case that leads him into the vast landscape of the North Frisian Wadden Sea. On Suunholt, a small, sleepy North Sea island near Denmark, a man was found dead who is no stranger in Kiel. Years ago Oliver Teuber was the key figure in a corruption scandal. The dead man had apparently found a new life and a new love far from Kiel. On Suunholt, the commissioner faces the completely disbanded Famke Oejen, who found her lover lifeless in her shared bathroom. Borowski is captivated by the mysterious atmosphere of the strange islanders.

In the middle of an event at the police college, a young student freaks out and stabs her buddy. He still dies at the scene in the arms of the helpless main commissioner.

Alarm in Kiel: In an uprising in the forensic clinic, the woman killer Kai Korthals manages to escape from security custody. Korthals, who crept and killed numerous women in their homes, became Borowski's personal nightmare six years ago when he kidnapped his fiancée Frieda Jung.

A killed infant is found in a parking lot near Kiels. Where's the mother? Did she kill her child? A found entrance volume leads Klaus Borowski and Mila Sahin to the sleepy town of Wacken in Schleswig-Holstein, which wakes up once a year when the world's largest heavy metal festival attracts 80,000 fans. The first trace leads the commissioners to Caterer Michi, who apparently took the young mother with him.