Just when Thomas and his pregnant fiancé Kerstin are at the wedding altar, his father, public prosecutor Bernd Reuther gets called to a dangerous operation. A man forced his way into the public prosecutor's office and took employee Susanne Selbach hostage. He insists to talk to Bernd in private. When the hostage-taker threatens to kill Susanne, Bernd comes to the office trying to save Susanne’s life. He recognizes the hostage-taker as former bank robber Ralf Bredendiek, whose case he led several years ago. Bredendiek got out of jail where he got infected with HIV and is about to die. He is on his last mission: to kill Bernd Reuther. Bernd tries to calm Bredendiek while he talks about the justice ascertainment errors and on top he admits another robbery – in which case somebody else got convicted for. Bredendiek puts the gun towards Reuther when a special unit officer kills the hostage-taker and saves Reuther’s life. However, the confession leads Reuther to do more research on the old case. Convict Lüders remains silent and is not at all interested in a renewal of the trial. Asking his son Thomas about the case is not helpful either, although he led the investigations back then, he feels now wrongfully criticized. Bernd’s ambitious colleague Adrian, who convicted Lüders back then, is still convinced that they got the right man. Bernd Reuther’s insistency leads eventually to a surprising turn in the case that was closed a long time ago…
Yet first, Thomas has to prove his innocence as he is under suspicion that he caused a hit-and-run accident after drinking at a wedding reception.
