Jimmie Allen, a shady bookie, is in love with Pearl Proctor, a greedy dance hall girl. He schemes to get her back after she rejects him; and along the way, he revives a failing Gilbert and Sullivan troupe.
Trouble begins when a hated cad of a sponsor is found murdered during the climax of a live radio show. A radio engineer then tries to solve the murder.
Lloyd Wilson, trusted employee of an investment firm, is suspected of theft when $20,000 in security bonds is stolen from his office. Tarzan, the Famous Police Dog, has an intuitive dislike of an apparently respectable citizen, and this leads Wilson and the police to the gang headquarters. Tarzan wins a public citation for his leading part in breaking the case against a desperate gang of criminals.
