"The Mystery of the Black Domino" was the first film directed in Brazil by a woman, the pioneer Cleo de Verberena. Marcos and Virgílio are medical students and share the same room. At the end of the first night of carnaval, Marcos finds the corpse of a woman, dressed as a black domino, inside the closet and accuses Virgílio of murder. Virgílio defends himself by saying that that was Cleo, wife of Commander Fernando Almeida, and that he found her in the corso asking for help, but Marcos question...