Los Angeles, California. A cop who, unhappy with his job, blames others for his work problems, is assigned to investigate the case of a prowler who stalks the home of a married woman.
Frank Johnson, a sole witness to a gangland murder, goes into hiding and is trailed by Police Inspector Ferris, on the theory that Frank is trying to escape from possible retaliation. Frank's wife, Eleanor, suspects he is actually running away from their unsuccessful marriage. Aided by a newspaperman, Danny Leggett, Eleanor sets out to locate her husband. The killer is also looking for him, and keeps close tabs on Eleanor.
The Los Angeles police know that Pete Ritchie has been bringing drugs into the city, but they can't pin a single piece of evidence on him. After many botched attempts to get at the crook, they resort to having cop Madeleine go undercover and seduce her way into Ritchie's circle. Before she can get anywhere, she's abducted by Johnny, a government agent posing as a thug. But Johnny and Madeleine have no idea they're on the same side of the law.
A down-and-out student is hired to kill a wealthy woman. When someone else is suspected of the crime, the student taunts police until they realize that they may have to wrong man.
In postwar Vienna, Austria, Holly Martins, a writer of pulp Westerns, arrives penniless as a guest of his childhood chum Harry Lime, only to learn he has died. Martins develops a conspiracy theory after learning of a "third man" present at the time of Harry's death, running into interference from British officer Major Calloway, and falling head-over-heels for Harry's grief-stricken lover, Anna.
On the beach one night, Christine Faber, two years a widow, thinks she hears her late husband Paul calling out of the surf...then meets a tall dark man, Alexis, who seems to know all about such things. After more ghostly manifestations, Christine and younger sister Janet become enmeshed in the eerie artifices of Alexis; but he in turn finds himself manipulated into deeper deviltry than he had in mind...
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.
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.