Marek Gorsky (Max Riemelt, Lukas Riemelt), son of Russian-Jewish immigrants, is a police officer in section 6 of the Berlin police force. When he and his friend and colleague Sven Lottner (Ronald Zehrfeld) were asked by the LKA to investigate organised crime, the trauma of his childhood caught up with him again: Grisha, his older brother, has been shot and killed by a criminal rival. The culprit was never caught. The investigations in the structures of organized crime become for Gorsky a hunt for the murderer of his brother Grisha. Together with his friend Lottner, Gorsky approaches more and more Mischa, the owner of the Odessa restaurant and husband of his sister Stella (Marie Bäumer). Gorsky has to make a decision: Is he turning against Misha and his sister Stella? Can he trust the young Ukrainian Yelena (Alina Levshin), who was lured to Berlin with her friend Svetlana (Katya Nesytova) to force her into prostitution here?