Claiming that he doesn't know his own past, a rich man enlists an ex-con with an odd bit of detective work. Gregory Arkadin says he can't remember anything before the late 1920s, and convict Guy Van Stratten is happy to take the job of exploring his new acquaintance's life story. Guy's research turns up stunning details about his employer's past, and as his work seems linked to untimely deaths, the mystery surrounding Mr. Arkadin deepens.
To make an honest woman of his pregnant sister, Rosalie, callous New York mobster Phil Regal intimidates witnesses and bribes a store clerk to get Rosalie’s condemned boyfriend, Nicky Bradna, out of prison. But Regal’s meddling deeds soon backfire.
Vicious gangster Vincent Canelli pulls off a daring prison escape just moments before going to the electric chair, taking with him Peter Manning – a bank robber and cop killer who was to die right after him. Taking several hostages along, they try to get their hands on the loot from Manning’s robbery to finance their escape from the country.
The tranquility of a small town is marred only by sheriff Tod Shaw's unsuccessful courtship of widow Ellen Benson, a pacifist who can't abide guns and those who use them. But violence descends on Ellen's household willy-nilly when the U.S. President passes through town... and slightly psycho hired assassin John Baron finds the Benson home ideal for an ambush.
While in London trying to nab several fugitives who stole a million dollars from a U.S. Treasury vault, American federal agent Dennison (Dennis O'Keefe) assists Scotland Yard Insp. McClaren (Philip Friend) in his search for a missing atomic scientist (Paul Hardtmuth). The detective duo discovers that the key to solving both cases may rest with the scientist's daughter (Margaret Sheridan) and her fascinating diamond.
A famed trumpet player is suspected of murdering a blues singer. Using only two minor clues, he narrows the suspects to four people, but only after surviving poison placed on the mouthpiece of his trumpet!
London, 1888: on the night of the third Jack the Ripper killing, soft-spoken Mr. Slade, a research pathologist, takes lodgings with the Harleys, including a gloomy attic room for "experiments." Mrs. Harley finds Slade odd and increasingly suspects the worst; her niece Lily (star of a decidedly Parisian stage revue) finds him interesting and increasingly attractive. Is Lily in danger, or are her mother's suspicions merely a red herring?
A scientist takes the brain of dead man and revives it via electrodes as it lays suspended in a tank of liquid. Soon, the brain grows to possess enormous psychic powers and inflicts its personality upon the doctor who saved it, creating a "Jekyll and Hyde" paradigm.
Roy and Gilbert's fishing trip takes a terrifying turn when the hitchhiker they pick up turns out to be a sociopath on the run from the law. He's killed before, and he lets the two know that as soon as they're no longer useful, he'll kill again. The two friends plot an escape, but the hitchhiker's peculiar physical affliction, an eye that never closes even when he sleeps, makes it impossible for them to tell when they can make a break for it.
In New York's 1880s newspaper district, a dedicated journalist manages to set up his own paper. It is an immediate success but attracts increasing opposition from one of the bigger papers and its newspaper heiress owner.
Canadian World War II veteran John Graham works in London as a code breaker. Tragedy strikes when his pregnant wife, Carol, is accidentally run over by two crooks who are speeding away from the scene of a murder. Haunted, grieving, and thirsting for revenge, Graham sets out to find the two fugitive murderers.