A petty thief schemes a big score when he plans an armored car robbery.

Vincent Lubeck is a vicious ex-convict. His criminal activities are despised by his family, but he uses and abuses them in the course of his crimes. Eventually his own brother must stand up to him.

Mota is a Martian representative, who has come to impose interplanetary law on the Earth (which has become too dangerous); opposing his authority is Kent Fowler, who resists the alien plot, without understanding its details.

Joyce Harper is an ex-Army nurse who enters police work with the L.A. Police Department, when her friend Ruby gets involved with a petty crook, Max Taylor refuses to listen to Joyce's warnings, and eventually marries the hoodlum. Joyce gets through the detailed trained required to become an L.A. policewoman, and she and her newly-assigned detective partner, Harvey Gates cleanup up a skid-row Bar-girl scheme.And she and Gates are told to get the goods on a narcotics gang ran by Richard Cott , and Ruby and Max Taylor reappear.

A police detective falls for the bank robber's girlfriend he is supposed to be tailing.