Politician/thug Paul Madvig (Brian Donlevy) is used to thinking with his fists; his right hand man Ed Beaumont (Alan Ladd) is used to thinking with his head. Both are best friends. Madvig throws his considerable political weight behind gubernatorial candidate Ralph Henry in order to win daughter Janet Henry's (Veronica Lake) affections. Paul also makes an enemy of a former ally, gangster Nick Varna, who has many of Janet's brother Taylor's gambling debts. Janet acts nicely towards Paul so that Paul will support her father but she is more interested in Ed. Ed is also attracted to her but backs off for Paul's sake. Ed and Paul disapprove of Paul's younger sister Opal (Bonita Grainville) dating Taylor (Richard Denning) because Taylor gambles. Outside the Henry home, Ed finds Taylor dead.
Ed and Paul fight over Janet. Ed goes to Nick Varna and implies he will reveal Paul's secrets, then changes his mind. Varna's thugs, Rusty and the sadistic, perverse Jeff (William Bendix), beat Ed savagely. Varna brings in the editor of the Observer newspaper, Matthews, to record Ed's confession of Paul's secrets, but Ed escapes and is hospitalised. In the hospital, Paul claims to Ed that he killed Taylor, but Ed thinks Paul is covering up for the real killer. He tracks Opal to Matthews' country residence and finds Opal, the Matthewses, Nick and his henchmen there. Nick is forcing Matthews to publish Opal's suspicions about Paul murdering Taylor. Matthews' trophy wife kisses Ed and Matthews commits suicide, but not before making his will. Ed destroys the will and gets Paul to get the estate administrator to kill the story about Opal's suspicions.
Ed searches for Nick but is cornered by Jeff. Jeff takes Ed up to his room and hints that Nick had something to do with Taylor's murder. Nick enters, fights with Jeff, and Jeff strangles him to death. Ed leads the police to the Henry residence to arrest the prime suspect--Janet. To save his daughter, Ralph confesses to accidentally killing Taylor after an argument. Paul had helped Ralph move the body. Ed prepares to move to New York. Janet, engaged to Paul, asks Ed to take her away. Paul gives his blessing to the couple but wants Janet's engagement ring back.