Paul Flemming finally listens to the voice of his heart and wants to propose to his girlfriend Katinka. But, as usual with his life plans, something gets in the way: the stage photographer of the Nuremberg Opera House is poisoned - and Paul is allowed to take over as his successor. It's not an easy legacy, as it doesn't stop with one murder, and soon the entire theater scene is in turmoil. Who is after the lives of the singers and their colleagues? Since the perpetrator leaves no traces and suddenly appears everywhere in the historic building, rumors of the "Phantom in the Opera House" soon begin to circulate. In his sixth case, amateur detective Paul Flemming investigates once again alongside his friends, Pastor Hannes Fink, tabloid reporter Victor Blohfeld, master chef Jan-Patrick from the Golden Knight, and Katinka's daughter, the spirited Hannah.