Dr. Mabuse and his organization of criminals are in the process of completing their latest scheme, a theft of information that will allow Mabuse to make huge profits on the stock exchange. Afterwards, Mabuse disguises himself and attends the Folies Bergères show, where Cara Carozza, the main attraction of the show, passes him information on Mabuse's next intended victim, the young millionaire Edgar Hull. Mabuse then uses psychic manipulation to lure Hull into a card game where he loses heavily. When Police Commissioner von Wenk begins an investigation of this mysterious crime spree, he has little to go on, and he needs to find someone who can help him.
A pampered American oyster tycoon decides to buy a husband for his daughter, but things don’t go quite as planned. Along the way there are mishaps, misunderstandings and a foxtrot sequence that must be seen to be believed.
The sinister Count Oetsch scandalizes the aristocratic social gathering at Castle Vogelod as he announces his intention to "crash" the festivities. Baroness Safferstätt is expected shortly, and the guests are well-aware of the rumors that Count Oetsch murdered the baroness' late husband. Oetsch refuses to leave, vowing that he will reveal the identity of the real killer. Before the weekend is through, the Count and Baroness will reveal secrets too shocking to be believed!
