Secret Beyond the Door...

G-Man Charles Bent Martin is sent out to break up a nationwide racket. A transport company is aiding fugitives making a getaway in exchange for the lion's share of their loot. Through an old friend, whom he once barnstormed in an air circus, Martin joins the gang as a pilot. He becomes interested in Carol Butler, a beautiful girl involved with the gang through the activities of her ne'er-do-well father.

A down-on-her-luck San Francisco woman, turning in desperation to jewel robbery, barely escapes getting nabbed in a heist and moves to Los Angeles where she gets an honest job as a waitress. Her troubles start again, however, when she falls madly in love, blind to the fact that her boyfriend is a four-flushing, small-time con man.

Naive young Wendy (Gloria Jean) lives with her kind Uncle Bill (John Qualen), who has sheltered her from life by instilling a belief in fairy-tales and make-believe. Uncle Bill, a pawnshop owner, buys a violin from shady character Peg-Leg ('Sheldon Leonard' )qv)). When Johnny (Keefe Brasselle, a neighborhood boy and friend of Wendy, connects the violin with the theft of a Stradivarius from a murdered composer, he is kidnapped by a group of thugs. Peg-Leg is killed by the boss of the crime-ring, a face-disguised mystery man known as Raincoat. He tortures Johnny to make him reveal his knowledge of the gang's activities. Meanwhile, Gloria his discovered the identity of 'Raincoat' and seeks the help of Mike (Bill Goodwin), the policeman on the beat.

Joyce Harper is an ex-Army nurse who enters police work with the L.A. Police Department. When her friend Ruby gets involved with petty crook Max Taylor, she refuses to listen to Joyce's warnings and eventually marries the hoodlum. Joyce gets through the detailed training required to become an L.A. policewoman, and she and her newly-assigned detective partner Harvey Gates clean up a Skid-Row bar-girl scheme. Then she and Gates are told to get the goods on a narcotics gang run by Richard Cott, and Ruby and Max Taylor reappear.

Assistant District Attorney P. Cadwallader Jones (James Ellison) and his sweetheart Terry Parker (Virginia Gilmore), a newspaper reporter, are about to be married when news comes that newspaper publisher Elliott Carter (Bradley Page) has been murdered. The marriage is postponed, and Jones is assigned to the case by his superior, District Attorney Winton (Paul Harvey) and obtains a conviction in court against Andrew Belmont (John Eldredge). Terry, however, discovers further evidence and Jones agrees to re-open the case.

Bill Sheldon has a grudge against Midland City newspaper publisher Brandon Williams as Sheldon blames the city's recent flood against Williams for using his power and influence to hold up government flood control money. When Williams is found murdered, Sheldon is charged with the crime that was actually committed by Walter Russell, the paper's rebel editorial writer. Ney York reporter Linda Ware arrives to cover the story and finds that Russell, her old sweetheart, is on the jury hearing Sheldon's trial. She also discovers that he is the killer. Russell forces an acquittal and, before another trial can be held, realizes that his conscience will not permit him to let Sheldon be tried again.