Ostfriesengrab

A young woman hangs, tied up on ropes, dead in a tree in the Schlosspark Lütetsburg –, obviously she was the victim of a cruel violent crime. The suspicion falls on the ex-prisoner Dieter Meuling, who had a love affair with the young woman. Meuling is arrested. Shortly afterwards, his lawyer answers with explosive information. Meuling found out from his former cellmate who is the murderer of Ann Kathrin Klaasen's father. He would tell her the name if the Commissioner helped him escape. Ann Kathrin agrees against the advice of her colleague Frank Weller. When Dieter Meuling does not want to reveal the murderer's name, she threatens him with the gun. But Meuling manages to escape. Kripo boss Ubbo Heide is beside himself.
He has no choice, he suspends Ann Kathrin Klaasen. A short time later, the body of another young woman is found on the beach, her body was up to her neck in the sand buried. The investigators finally manage to face the fleeting Dieter Meuling, but the situation derives within seconds: Meuling is armed and takes a hostage. Weller is forced to shoot – Meuling collapses fatally and takes the knowledge of the murderer of Ann Kathrin's father to the grave. It returns to rest in East Frisia. But soon a third body appears. A young man was tied to a concrete block in the mudflats and drowned in the flood. It seems to be the same perpetrator, Meuling was apparently innocent.
Then the daughter of the famous artist Freimut Diebold, who is currently in his home country, disappears to celebrate his life's work with a retrospective. Ann Kathrin Klaasen suspects that the murders have to do with the four elements and that the young woman will be the last victim for the final „ fire scenario ". A race against time begins for the investigators.