Rusty Noonan, a wisecracking mechanic with a chip on his shoulder, inadvertently kills his boss at Detroit's United Taxi Co. during an argument. In a panic, he runs away, heading West. While walking through the desert, he stops to fix Ann Vangarick's car, and she offers him a lift in return. He has heard that there is plenty of construction work at Boulder Dam, but when he shows up several days in a row without getting hired, he leaves in a huff. He meets Ann again in the Las Vegas club where she is a singer. Over dinner, he tells Ann his name is Joe Callahan. Wanting to give him a break, she invites him home for the night, but when he makes a pass at her, she straightens him out right away. Her family, recent immigrants, are generous people. Slowly, Rusty accepts their good will, and one night when the men are talking about how much the dam means to them, Rusty decides to reapply for work there. Under Ann's influence, he rapidly makes good, and when he unloads a runaway dynamite truck, he is suddenly a hero. Shortly afterward, Agnew, the head of the project, promotes Rusty. Feeling accepted for the first time, Rusty asks Ann to marry him and she gladly agrees. As he celebrates his engagement with some of the men, Lacy, a former suitor of Ann, reveals that he knows Rusty's real identity and threatens to tell the police if Rusty doesn't leave town alone within twenty-four hours. Before he can make good on his threat, however, a carrier cable breaks, placing Lacy's life in danger. Selflessly, Rusty rescues him and realizes that he must tell the truth about himself. When he confesses to Agnew, he is told that he must return to Detroit to take his punishment, but that the company will stand by him as will Ann.
