Hitman Raven (Alan Ladd) coldly carries out his assignment by murdering a chemist and his sleazy secretary and stealing Baker's chemical formula. Raven gives the formula to his employer, who blunders trying to hide his identity as Willard Gates, a manager for Nitro Chemical Corp. Gates double crosses Raven by paying him in marked bills. Raven eludes the cops and travels to LA to exact revenge from Gates.
Meanwhile, magician Ellen Graham (Veronica Lake) successfully auditions for a gig in Gates' Los Angeles nightclub The Neptune. (Yes, chemical plant manager by day, nightclub owner by night--that Gates is a busy man.) Ellen is also working secretly undercover for Senator Burnett, who suspects Nitro Chemical Corp. of selling secrets to enemies of war. She's in a bind because she can't confide in her detective boyfriend Michael, who's after Raven. On the train to LA, she meets Raven. Gates sees the duo and calls the police. Raven eludes the cops again by taking Ellen hostage. Eventually, she escapes.
Gates invites Ellen to his house and plans to have his chauffer kill her while he's at the club. Raven rescues Ellen and takes her hostage again. At the Neptune, Michael and Gates spot them, but they get away to near the railroad tracks. Ellen changes her mind from wanting to be rescued by the cops. She diverts their attention and allows Raven to escape.
Raven goes to the Nitro building where Gates' boss, Brewster, is planning to hand over the chemical formula for poison gas to the Japanese. Brewster tries to kill Raven but keels over from a heart attack. Raven kills Gates and prepares to shoot Michael, who is dangling on a scaffold outside the building. However, he pauses because he sees Ellen rescuing Michael from the scaffold. The police enter Brewster's office and shoot Raven. Raven asks Ellen if he did allright, she says yes and he dies. Ellen and Michael embrace.