Synopsis: from TCM
Johnny Davis, the son of gambler “Natural” Davis, Byron “By” Newbold, the son of crusading newspaper editor Barton Newbold, and Kate Pendleton, the daughter of Clare Pendleton, a wealthy widow and sportswoman, are schoolmates. Barton Newbold, who is determined to publicize Natural’s illicit activities, organizes a raid on Natural’s casino, which Natural foils by quickly transforming the gambling room into a musical recital. Newbold’s men follow Natural to Lucille Baker’s apartment, where Natural accuses her of blackmailing him and his sweetheart Clare, until he realizes that Lucille is dead. Natural finds a gun near the body, and as soon as he picks it up, Newbold’s men enter and accuse him of murder.
A jury convicts Natural of first degree murder, and he is sentenced to ten years in prison. When Johnny visits his father in jail, Natural tells him that he has been placed in Clare’s custody. Later, Johnny picks a fight with By, blaming his father for printing lies about Natural, and By punches Johnny. By gives Johnny a chance to prove his father’s innocence by organizing a private investigation of Lucille’s murder. Picking up the murder trail with a clue found in his father’s office, By leads Johnny and Kate to Lucille’s apartment building, where they question Madame Wachek, the building manager. Madame Wachek shows Kate a picture of Lucille’s baby boy, which Kate immediately recognizes as Johnny. Shocked and bewildered, Kate runs off with the picture before Johnny sees it. When Kate shows her mother the picture, she is told the truth about Johnny–that when he was a baby he was abandoned by his mother, Lucille, and that after his father, a friend of Natural’s, died, Natural adopted Johnny.
Clare also explains that since then Lucille has demanded money to keep the truth about Johnny’s parentage a secret. Later, a clue furnished by Madame Wachek leads the sleuthing threesome to the apartment of another tenant, Al Posna, who, to Madame Wachek’s surprise, has secretly vacated his apartment. Inside the nearly empty apartment, Kate finds a sheet of music, plays the song on the piano and memorizes it in the hope that she will find the murderer when she hears it played. Kate’s theory proves correct when they hear the song and locate Posna, who is using the name Al Milbar and running a nightclub show.
With the help of their school classmates, Kate, Johnny and By cleverly decide to stage a play inspired by Hamlet , written in such a way as to provoke a confession from Posna. In the third act of the play, when Johnny and Kate play out a scene depicting the murder of Lucille, Posna panics, takes Clare as a hostage and tries to flee. By saves Clare by knocking Posna unconscious with a baseball. With Posna exposed as the murderer and Natural exonerated of the crime, Johnny and By make amends and Natural and Clare get married.