In 1932 Waycross, Georgia, teenager Sonora Webster bobs her own hair, infuriating her guardian, Aunt Helen. On the way to school, Sonora accepts a challenge from her classmate, Clarabelle, to jump a cow pasture fence on horseback. The fence is damaged during the jump, and Sonora is late for school after rounding up the stray cattle. At school, Clarabelle taunts Sonora, who punches her in the face. Their teacher, Miss Simpson, gives Sonora a week’s suspension and notifies Aunt Helen. That afternoon, Sonora notices a newspaper advertisement, stating that Dr. W. F. Carver is seeking young women to ride diving horses for his carnival attraction. Upon her return home, Aunt Helen tells Sonora she is “nothing but trouble,” and is being sent to a state facility. Late that night, Sonora makes her way to the county fair, intent on becoming a “diving horse girl.” As she wanders midway, Sonora encounters a group of men accusing Dr. Carver’s son, Al, of cheating in a poker game. When the Ace of Hearts falls from Al’s hat, Sonora comes to his aide by covering the dropped card with her foot. Later, hotdog vendor Clifford Henderson directs her to Dr. Carver’s tent, and she waits outside while the showman scolds Al for his habitual gambling. After Al leaves, Sonora introduces herself, claiming to be the ideal candidate for his new diving horse girl. Dr. Carver dismisses Sonora, saying she is too young. Annoyed with her persistence, Dr. Carver carries Sonora outside the tent and advises her to go home. Undaunted, Sonora approaches Al and presents the playing card, implying that he owes her a favor. Al explains the details of the job but also apprises her of the negative aspects, including his father’s severe nature. In the stable, Sonora impresses Dr. Carver with her empathy for horses, and he hires her to work as a stable hand at his ranch in Virginia. One day, Al arrives at the ranch with an untamed horse he won in a card game. Despite warnings to avoid the horse, Sonora trains the animal and names him “Lightning.” Sonora and Al develop a mutual fondness, and she tells him of her ambition to be an entertainer in Atlantic City, New Jersey. She becomes jealous upon learning that Al and Marie are dating, and enhances her appearance to draw Al away from her rival. Al invites Sonora to go swimming in the moonlight, but when he tries to kiss her, she becomes frightened and runs to her room. Believing she has proven herself capable, Sonora asks Dr. Carver for an audition as a diving horse girl. He promises Sonora the opportunity if she can mount a moving horse. At her employer’s urging, Sonora makes numerous attempts and receives several bruises before she succeeds. Al is angry with his father for putting the girl at risk, and following a heated exchange, he leaves the ranch, promising to write to Sonora while he is away. However, when Al’s letters arrive, Dr. Carver destroys them without Sonora’s knowledge. Later, Marie sustains a dislocated shoulder after being thrown from a horse, and Sonora is trained to replace her. Upon witnessing Sonora’s successful performance, Marie refuses to share billing “with a stable hand” and quits to become an actress in New York City. Although pleased with her success, Sonora is heartbroken over not hearing from Al. Threatened with financial ruin by the Great Depression, Dr. Carver goes in search of more prosperous venues, accompanied by his new stable hand, Clifford Henderson. Al’s travels conclude with a trip to Atlantic City, where he discusses a business proposal with Mr. Slater, manager of the Steel Pier. Upon his return to the ranch, Al and Sonora have a joyful reunion, and nurse Lightning through an attack of colic. Although Dr. Carver is happy to see Al, he believes the show is doomed, until a telegram arrives from Mr. Slater, asking to negotiate a six-month contract. On the way to Atlantic City, Dr. Carver expresses his regret over destroying Al’s letters, then complains of ill health. Sonora, Al, and Clifford set out a picnic lunch, while Dr. Carver rests under a tree and dies in his sleep. Although they are saddened by the showman’s death, the team continues to their destination, and Al replaces his father as master of ceremonies. Because Lightning has not fully recovered from his illness, Sonora makes her Atlantic City debut on Red Lips, a horse that can be difficult to control. As Sonora climbs the tower, Al proposes to her over the public address system. She is initially flustered, but accepts the proposal to the cheers of the audience. As a band plays below, Sonora and Red Lips proceed with the dive, but a cymbal crash spooks the horse and he falls into the tank sideways. While Red Lips emerges unscathed, Sonora has difficulty seeing, due to her eyes being open when she hit the water. Days later, a doctor determines that her retinas have detached, and she will never regain her eyesight. Desperate for a replacement rider, Al invites Marie to return to the show. Meanwhile, Al helps Sonora adapt to her condition, and Clifford develops a “death-defying” attraction in which he rides a motorcycle inside a spherical cage. His achievement reminds Sonora of the value of perseverance, and she is determined to become self-sufficient. Sonora offers to cancel the wedding, fearing Al might feel obligated by her disability, but he dismisses her concerns. Although Sonora desperately wants to continue diving, she consistently fails to mount a moving horse, and her confidence erodes. However, after an evening getting reacquainted with Lightning, Sonora believes she is ready to dive again. In the morning, Sonora conspires with Clifford to lock Marie in her trailer and take her place, despite objections from Al and Mr. Slater. The dive is successful and the crowd responds enthusiastically, unaware of Sonora’s blindness. Sonora and Al are married soon after, and she continues as a diving horse girl for eleven more years.