Willis Newcomb and Bart Carroll head a gang engaged in smuggling wanted-American criminals back into the United States from Mexico. Operating from Sharperville, an oil town on the American side of the border, they transport their human cargo in oil drums loaded on trucks. Border Patrolman Tom Sharper intercepts one of the trucks but is overpowered and left for dead. Carroll, having already been paid for the job and not wanting any evidence to walk around, get caught and lead back to him, backs the human-cargo trucks to the edge of a cliff and sends the drums crashing to the boulder far below. Judge Cookie Bullfincher and Border Patrolman Roy Rogers conduct a search for the missing Tom, but the crooks have gone back for him and find him in a state of amnesia. They rob the bank and pin it on Tom. It is now up to Roy to clear his friend and also put an end to Carroll’s human-smuggling racket.
Dorn is after the rancher’s land and is trying to stop Banker Brady from helping them. When his man Hammond kills Brady, there is a run on the bank. When Rocky volunteers to ride to the next town for money, he is ambushed by Dorn’s men, loses his memory, and is jailed for supposedly stealing the money.
One of several remaining members of its race, an alien from Venus is guided to Earth by disgruntled scientist Tom Anderson, who tells it which humans it should attach mind control devices to. Among them is his old friend, fellow scientist Paul Nelson. Nelson, after killing a flying bat-thing which carries the device, finally persuades the paranoid Anderson that he’s been wrong to ally himself with an alien bent on world domination. They hurriedly leave when they discover Tom’s wife has picked up a rifle and gone to the alien’s cave to try to kill it.
New York gambling house operator Johnny O’Clock is junior partner in a posh casino with Guido Marchettis and Chuck Blayden, a crooked cop. But Blayden is trying to cut into the casino’s profits and warns Johnny not to interfere with his intention of becoming Marchettis’ full partner. Blayden ends his relationship with coat check girl Harriet Hobson, then disappears. Later, Harriet is found dead in her apartment, apparently from suicide. Police Inspector Koch begins an investigation.He questions Johnny, Harriet’s sister Nancy, who is infatuated with Johnny, and Johnny’s associate, Charlie. When Blayden’s body turns up in a nearby river, and when it is learned that Harriet death wasn’t suicide but murder by poison, Johnny and Marchettis become prime suspects in both cases.To make matters worse, Pete Marchettis discovers that his wife Nelle is having an affair with Johnny. Out of jealousy, he sends hired gunmen to kill Johnny in a drive-by shooting while Johnny is driving Nancy to the ..
John Muller, medical school dropout and brilliant crook, plans a holdup which goes a little bit wrong, and finds vindictive gambler Rocky Stansyck after him. At the end of his tether, he stumbles onto a lucky chance to assume an impenetrable new identity as psychiatrist Victor Bartok. But irony piles on as Muller finds it’s out of the frying pan, into the fire.