Mad Youth is a 1940 American exploitation film. This gritty little film is also known as Girls of the Underworld (American re-issue title). The movie's story centers on the relationship between rich society mother Lucy Morgan (Betty Compson) and her daughter Marian (Mary Ainsley). The divorced Lucy is lonely and hires expensive male escorts to go with her to various parties and events. While Lucy is out on the town with gigolos, her wild child daughter Marian throws crazy house parties. Lucy's favorite escort is Count DeHoven (Willy Castello). The count, however, is not interested in Lucy and instead starts dating Marian. When her mother finds out about the affair Marian decides to leave town. She visits an old friend that she thinks is happily married, but in reality her friend has been forced into a life of prostitution. Soon Lucy is also forced to work as a prostitute, and the film builds to an unexpected conclusion.