Paris, France, December 1946. Jenny Lamour, an ambitious cabaret singer, and Maurice, her extremely jealous pianist husband, become involved in the thorough investigation of the murder of a shady businessman, led by Antoine, a peculiar and methodical police inspector.
A gang of criminals, which includes a piano player and an imposing former convict known as 'Gruesome', has found out about a scientist's secret formula for a gas that temporarily paralyzes anyone who breathes it. When Gruesome accidentally inhales some of the gas and passes out, the police think he is dead and take him to the morgue, where he later revives and escapes. This puzzling incident attracts the interest of Dick Tracy, and when the criminals later use the gas to rob a bank, Tracy realizes that he must devote his entire attention to stopping them.
Jim Ackland, who suffers from a head injury sustained in a bus crash, is the chief suspect in a murder hunt, when a girl that he has just met is found dead on the local common, and he has no alibi for the time she was killed.
Sandra Carpenter is a London-based dancer who is distraught to learn that her friend has disappeared. Soon after the disappearance, she's approached by Harley Temple, a police investigator who believes her friend has been murdered by a serial killer who uses personal ads to find his victims. Temple hatches a plan to catch the killer using Sandra as bait, and Sandra agrees to help.
Scotland Yard Inspector Geoffrey James comes to the United States looking for a band of international gem-thieves who have smuggled a rich load of jewels from England to America via a trans-ocean airline. Mary Hogan, an airline hostess, aids him in his quest.
Hoppy, California and Lucky take refuge from a storm inside a supposedly abandoned church outside a ghost town, only to meet a young woman and her mother there, then find themselves surrounded by a gang of "workmen" intent on tearing down the church if they have to kill the five to do it.
Up-and-coming Hollywood actor/crooner, Vic Morton, has a secret. He starts receiving death threats in the mail and an attempt on his life is made. Soon after, two of his associates are murdered. Who is behind it all?
When his best friend is murdered inside a London dancehall, a cab driver and his girlfriend involve themselves in the investigation and discover a major criminal operation hiding behind the club's friendly facade.
The dream is unusually vivid: Bank employee Vince Grayson finds himself murdering a man in a sinister octagonal-shaped room lined with mirrors while a mysterious woman breaks into a safe. It is so vivid that Vince suspects it may have really happened. To get the dream off his mind, he goes on a picnic with some relatives. When a thunderstorm forces his party into a nearby mansion, Vince discovers that the bizarre room does exist, and it means nothing but trouble.
A private detective, who has been shot, stumbles into the office of Michael Shayne (Hugh Beaumont), and dies before Shayne can question him. Shayne finds a baggage ticket in his hand. He claims it and finds the checked-bag contains the loot from a robbery. Now, he has about fifty minutes left of the running time to find the crooks, bring them to justice and return the money to the rightful owners. And needs all of it.
Ronnie Jackson is a lowly baby photographer who secretly fantasizes about being a private detective. When a lovely baroness actually mistakes him for one and asks him to help locate her missing husband, Baron Montay, Ronnie finds himself agreeing. Several days later he is on death row whiling away the hours until his execution by recounting to a group of reporters the bizarre tale of how he ended up there.
An old man and his sister are concealing a terrible secret from their adopted teen daughter, concerning a hidden abandoned farmhouse, located deep in the woods.
A woman is married to the son of a doctor, the proprietor of a private sanatorium, where she is under unwilling treatment. Both the son and the doctor indicate they want the marriage dissolved. Arriving at the scene is a mysterious personage identified as the doctor's cousin who formerly was a stage magician in Europe. He is accompanied by a threatening dwarf.