Ellen Crane, a compulsive gambler from Park Avenue, is badly in debt to Lonnie Burns, the owner of a nightclub. After he threatens to have her arrested for writing a bad check, Lonnie deals her one last card trick: if she wins, he will forgive her debt but if she loses, she must marry him. She loses, but escapes the nightclub and prepares to leave town. Burns hires private detective J. D. Storm to return Ellen to him, and J. D. follows her to Chicago, where she convinces a hotel bellhop named Joe to escort her to a gambling club. There she makes enough money to get to Los Angeles, and when she finds J. D. in her hotel room, she knocks him out and escapes. In Los Angeles, Ellen is befriended by an ex-convict named Beady, who suffers from agoraphobia as a result of a prison term. One night, Beady warns Ellen that J. D. has found her, and is arrested along with Ellen for shooting craps. Afraid Beady will have a nervous breakdown if he is forced to return to jail, Ellen offers to go peaceably with J. D. for twelve hours in exchange for her and Beady's bail. As Ellen and J. D. drive east in her new car, he begins to fall in love with her. She is determined to free herself, however, and has him arrested for abduction as soon as the twelve hours are up. J. D. retaliates by calling Burns and giving him their whereabouts. He later convinces the sheriff that he and Ellen are merely having a marital spat, and is released. As J. D. and Ellen camp, he asks her about Tom Priestley, her fiancé who died in the war, and learns that she blames her father, who forbade the marriage, for Tom's death. It is J. D.'s theory that Ellen gambles in an attempt to bankrupt her father, who has always supported her. The next morning, while attempting to escape, Ellen crashes her car, and it lights on fire. After J. D. saves her and lands in the hospital, Ellen realizes she loves him. Determined to rid herself of her compulsion to lose money, Ellen goes to Las Vegas. J. D., meanwhile, arranges for a justice of the peace to marry them upon her return. When she arrives at the hospital, having "cured" herself, she finds Burns waiting for her, and believes J. D. has double-crossed her. J. D., an ex-football player, successfully beats up Burns and his henchman, Oscar, however, and demands that Burns hand over Ellen's bad check. She then discovers that Burns used a loaded deck for their marriage bet. Leaving Burns and Oscar in a heap on the floor, J. D. carries Ellen out to get married.