In Frankfurt, tax lawyer Dr. Bernd Hausner and the young Sven Lebert set up a fund based on the double refund of capital gains tax: so-called Cum-Ex transactions.

In Germany and Denmark, legislation is being drafted in parallel to prevent cum-ex transactions. However, in both countries, the banking lobby is succeeding in influencing the legislation.

Hausner and Lebert realize that their business partner, Fred Allen, has been cheating on them for years; they can't report him. For the first time, Lebert considers a future without his mentor.

Young tax official Anna Nowak refuses to reimburse Hausner and Lebert's funds worth millions. She informs public prosecutor Lena Birkwald, who takes over the case.

Public Prosecutor Birkwald and her team are slowly becoming aware of the extent of the cum-ex transactions. She is pursuing a plan to conduct simultaneous searches in 16 countries.

The worldwide searches were a complete success for Public Prosecutor Birkwald – much to the displeasure of Hausner and Lebert. Lebert also learned that he had been let down by her.

With Lebert's help, investigative journalists Liholt from Copenhagen and Fromm from Hamburg deceive the Cum-Ex fraudster Akram and get a picture of the shocking extent of the scandal.

Lena Birkwald succeeds in making the extent of tax fraud clear to the Finance Minister of North Rhine-Westphalia. But Birkwald also wants to get to grips with the institutions themselves: the banks.