Gabriel Bach is an anti-terrorism investigator with the Hamburg State Criminal Police Office. The terrorist El Adoua was killed during a raid in Italy, but is believed to have previously spent several days in Hamburg. Gabriel and his colleague Holly Valentin are now tasked with investigating whether the terrorist in question was planning an attack in the Hanseatic city. The investigative duo have very different working styles and also clash personally. While Holly works coolly and in a controlled manner, Gabriel is impulsive and allows the investigation to smack into his personal life.

An attack in Hamburg leaves many injured and dead. In the chaos of the hospital, Holly's supervisor, Edgar Braun, tries to extract information from the perpetrator. But he arrives too late. A few weeks earlier, the investigative team of Gabriel Bach and Holly Valentin follows a promising lead. With the help of their informant Raza, they manage to identify the previously unknown "Big Shot". It is drug dealer Gol Rahmani. Is he planning an attack on the upcoming concert at the Elbphilharmonie? Gabriel and Holly have little time to prevent the worst. When the unlikely pair of investigators finds freshly printed money that can be traced back to "Big Shot", they suddenly seem to be confronted with higher political authorities.