Johnny Kelly (Gig Young) is a Chicago cop from a long line of police officers. He's grown tired of the job and his married life. Haunted by echoes of his mother-in-law's scolding voice, he plans on leaving his wife Kathy (Paula Raymond) for exotic dancer Sally "Angel Face" Connors (Mala Powers), but Sally is getting tired of waiting for him. Also in love with her is a club entertainer, Gregg, who mimics a mechanical man in his act.
Penrod Biddel (Edward Arnold), a corrupt, powerful attorney, wants Johnny for a job. Johnny is tempted because he needs money to move to California and start a new life. While still on duty, Johnny agrees to "escort" a low-life former magician Hayes Stewart(William Talman), now a criminal, across the border to Indiana, where apparently Hayes will permanently stay out of the way.
Hayes has been attempting to blackmail Penrod, crack his safe and find documents to use against him. It turns out Hayes' accomplice is Penrod's own wife, Lydia. As soon as Hayes hears about Penrod's plan to use the cop Johnny, he confronts Penrod, who is shot. Then he kills Lydia as well, in front of an eyewitness, Gregg.
Kathy goes to her father-in-law and says she might quit her job and try to make Johnny happier at home. His mind still playing tricks on him, Johnny goes after Hayes, accompanied by a mysterious sergeant called Joe, who may or may not be a figment of Johnny's imagination. Johnny becomes more disturbed when his father, a 27-year veteran of the force, is killed by Hayes, who mistook father for son.
Hayes goes to the club and spots the mechanical man, but can't tell if it's a robot or man pretending to be one. Someone else notices teardrops rolling down the robot's eyes, so Hayes opens fire. Gregg is wounded but not killed and Sally suddenly realizes how much she cares for him. Johnny arrives and chases Hayes to an "el" train, where Hayes is accidentally electrocuted. Johnny decides to stay on the job, with Kathy by his side. Joe just disappears.
Who is Haye's accomplice ?
Lydia