It's the day of the big concert at the Elbphilharmonie, but the investigative team is no longer there: Holly has been removed from the case due to serious errors in the investigation, and Gabriel is taking the reins himself to prevent the attack in his own way. At the same time, his old identity, "Charlie", is getting dangerously close to his family. Holly now wants to meet with Gabriel's wife and confide in her the whole truth about her former investigative partner's second identity. Events are unfolding rapidly. Are the personal problems of Gabriel, Raza, and Holly taking so much of a role that they're losing sight of what's important?

Gabriel and Holly's anti-terror team is threatening to fall apart. While Gabriel wants to focus on the trail of Gol Rahmani, Holly tries to redirect the investigation with new information. Holly wants Gabriel to take a break from the investigation. He then loses control and punches the senior BKA investigator Braun in the face. Dadir awakens from his coma and confides in Braun and Holly that Raza shot him. As a result, Raza is suspected of attempted murder and pursued by the SEK. Holly has Raza's father, brother, and girlfriend brutally arrested. At the same time, Raza makes the crucial discovery: Javid has amassed a supply of propane cylinders, enough for an attack on the Elbphilharmonie. While Holly has to answer for the arrest of Raza's family and is taken off the case, Gabriel and Raza hatch a disastrous plan...

Raza is being infiltrated as an informant by anti-terror investigators Gabriel and Holly, who are increasingly drawn into suspicious circles. There, it is suspected that drug dealer Gol Rahmani, alias "Big Shot," is planning a terrorist attack on the Hamburg Elbphilharmonie. Raza is becoming increasingly self-confident, allowing his old life to fade further into the background. Investigator Gabriel knows this temptation all too well: He finds it difficult to separate himself from his identity as an undercover investigator in neo-Nazi circles. As "Charlie", he visits his old "friends". His wife Emilia discovers that her husband never truly ended an affair in the right-wing extremist scene. Seeking help, she turns to Holly to learn more, but she remains silent about Gabriel's secrets. Both Gabriel and Raza must make decisions in their parallel lives that have serious consequences...

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.

Gabriel Bach and Holly Valentin, investigators from the Hamburg State Criminal Police Office (LKA) and the Federal Criminal Police Office (BKA), are working to prevent a potential terrorist attack in the Hanseatic city. Raza, a German-Afghan substitute teacher who doesn't really have anything to do with crime, becomes vulnerable to blackmail after an incident with the police at a party. Gabriel and Holly then use him as an informant in the Islamist scene. Dadir, brother of the murdered drug dealer Youssef, seems to be the right initial contact for him. Raza soon provides another interesting lead. The terrorist El Adoua is said to have actually met with the ominous "Big Shot". Although Gabriel is now investigating the Islamist milieu, he seems unable to escape his past as an undercover investigator in neo-Nazi groups: As "Charlie," he mingles with his old "friends". Will this relapse jeopardize his current investigation and possibly even his private life?

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.