A federal tax agent goes undercover as a reporter and, working with a mobster's pretty bookkeeper, infiltrates a crime ring to catch the racketeer. When she agrees to testify, an informant exposes them and she's kidnapped.

After Police Captain Dan McLaren becomes police commissioner, former detective Johnny Blake publicly punches him, convincing rackets boss Al Kruger that Blake is sincere in his effort to join the mob. "Bugs" Fenner, meanwhile, is certain that Blake is a police agent.

A corrupt official at San Quentin tries to frame an innocent guard for several murders within the prison.

A reporter and a lawyer investigate a women's prison and help an inmate who does not belong there.