When a play's two producers are murdered, the playwright tries to solve the crime.

A cowboy and sidekick infiltrate a rustler gang to avenge the murder of their pal.

Dan Adams resigns his position as prosecutor on the district attorney's staff and sets out to clean up a gang of fake-accident racketeers. He gets a job with an insurance company, and assures the company president he will get the goods on the gang or die in the attempt. At the company offices, he meets Carol Carter and she, believing he is a shyster (possibly redundant) lawyer in the employ of the racketeers gives him as little help as possible. Dan visits his brother Eddie, who is mixed up with the gang and tries to make him break away. Eddie is belligerent but finally, because of the pressure brought by Dan and his wife Tonia, agrees to go straight. The gang, led by "Duke" Trotti, fears he will squeal and they kill him, plus they make his death look like an accident and plan to collect on it. Dan is closing in on the gang when Carol, who is now his assistant, comes up with some conclusive evidence, but "Duke" has plans to get rid of her before she can give the information to Dan.

Four "Picture Brides", from New Orleans, arrive in the Brazilian jungle on a riverboat, brought there to marry workers at Lottagrasso, a remote mining site of the Standard Diamond Mines. Also on the boat with the four "mail-order" brides (Americans Mame Smith, Flo Lane, and Gwen from England and Lena from Europe) is Mary Lee, a frightened and innocent girl, who has come to see the mine's brutal supervisor, Von Luden, about a job.

A man is blamed for a murder that was actually committed by his wife.

Chan is faced with suspects in a stolen atomic bomb formula case, that are being killed with bullets that are not fired from a gun.

The relatives of a rich old woman unsuccessfully try to have her declared insane, so they can divide up her money. To show them that there are no hard feelings, she invites them to her estate for the weekend so she can decide to whom she actually will leave her money when she dies. Soon, however, family members begin turning up dead.

A recently released prisoner lives alone in his cabin so that his bad temper won't get him back in any more trouble, but his peaceful existence is disrupted when a mysterious woman arrives.

Chinese sleuth Charlie Chan discovers a scheme for the theft of government radar plans while investigating several murders.

Charlie Chan is an agent of the US government working in Washington DC and he is assigned to investigate the murder of the inventor of a highly advanced torpedo. Aiding Chan is his overeager but dull-witted son Tommy and his daughter Iris.