Frank, a man without a criminal record, attacks a money transporter and then turns himself in to the police. His behavior is a mystery. In prison he meets the unscrupulous and suspicious Arab Fuad, who is protected by his clan. To get closer to Fuad, Frank intervenes in the drug business within the walls and gets caught between the two rival groups of German and Arab inmates. It is only the prison guard Susanna with whom Frank will be able to build a relationship of trust, not knowing that she is part of Fuad’s business and has a sexual relationship with him. However, they come emotionally close. What only Frank knows is that his wife and his daughter died in a car accident. Fuad was the hit-and-run driver that remained unpunished. Frank seeks revenge.
Youssef's niece Saida finds her boyfriend, the young doctor Hagen Hoffmann, slain in their shared apartment. Based on the victim's computer activities, the police assume that the crime was committed in a drug environment.