Elisabeth is persuaded to have killed her noisy upstairs neighbor, scientist Charles Magne. To save her, Mr. Matheu, Elisabeths father, accuses himself while Pierrot, Elisabeths fiancé gets rid of the body in order to save father and daughter. For his part, a gangster also believes he has killed the scientist but he gets shot down by a taxidermist, who runs for life. The girl, her daddy and her boyfriend also run away. But Magne is not dead. A bum is mistaken for him and a police inspector makes everyone believe that he is the one who shot the gangster. At the end of this crazy chain of events all the protagonists are reunited at the station house and everybody dances to express their relief.