Munich investigator Ali Zeller has to transfer an arrested soldier from Austria to Germany. On the way, a fatal catastrophe occurs on a highway bridge.

Ali is blamed for the bridge collapse and suspended from duty. Through his brother Leo, he learns that the prisoner was involved in an arms deal.

Ali and Leo almost miss the weapons container in the port of Athens. In Munich, Maryam prepares the compensation trial and comes across inconsistencies in the construction of the bridge.

Back from Greece, Ali and Leo realise that they are involved in a dangerous conspiracy. Maryam is threatened and is told to stop her research into the bridge collapse immediately.

While Leo wants to expose the perpetrators, Ali and Frida hide in the Alps. Maryam refuses to be intimidated and attracts the attention of new opponents.

Ali and Leo want to catch Maryam's attackers - a wild chase ensues with fatal consequences. Building contractor Leif Lohberg has to answer for the bridge collapse.

Ali and Leo are blackmailed. They are supposed to take on an old case and find the missing Phillip Münch, who most recently worked as a drug courier.

Maryam finds herself in more and more danger as a result of her research. Meanwhile, Edda Münch, driven by revenge, takes extreme measures and gives Ali and Leo an ultimatum.

Nora and Maryam are offered a lot of money to finish their research. Lohberg is supposed to testify in court and Jannis discovers evidence that incriminates Leo and Ali.

After an assassination attempt on a journalist, Ali and Leo also find themselves in the line of fire: in the final duel they face a contract killer.