Nick Conover, a callous Chicago youth, arrives in Kentucky horse country to stay with his uncle Jed and aunt, Henrietta Bruce, at their horse ranch. Nick is on probation for stealing a car, and consequently, his mother has sent him to her sister Henrietta in hopes of shielding him from the evil influences of the city. Nick, sullen and resentful, clashes with the gruff Jed, who has grown distant and irritable ever since the death of his beloved son Jed Junior in the Korean War. Soon after, Liz Templeton, the tomboyish daughter of a neighboring rancher, invites Nick to her family's ranch. In contrast to the austere Bruce ranch, the Templeton ranch is teeming with beautiful race horses gamboling on well-manicured pastures. Liz explains that after his son's death, Jed retreated from life and sold all his horses except the high-spirited Tugfire, Jed Junior's favorite. At the ranch, Nick meets Fran, Liz's glamorous sister, when she drives up in her sports car with her boyfriend, Al Turner. Nick, an avid mechanic, admires Fran's car and she offers him a ride, but is soon stopped for speeding by Joe, the local constable. That evening, Nick sneaks into his uncle's garage and fixes the broken-down tractor. After presenting Jed with the now-running machine, Nick asks for permission to work on the old jalopy. Liz, who has developed a crush on Nick, invites him to join her at the dance, but soon realizes that he is infatuated with her sister. After repairing the jalopy, Nick races it around the farm, spooking Tugfire, who jumps the fence of his corral and gallops off. When the horse falls and becomes entangled in the underbrush, Nick frees the animal and they become friends. Nick then leads Tugfire home, and Jed, astounded by Nick's newfound rapport with the horse, decides to train the boy to drive a sulky. As Nick masters the handling of the trotter, Jed renews his interest in racing and life. One day, Liz invites Nick to join Fran and Al for a barbecue at the Templeton ranch. When Nick drives up in his jalopy, Fran challenges him to a race that ends when she crashes her car through a fence. Feeling guilty, Nick confesses to Liz that he had his driver's license suspended for stealing a car. Back at the Bruce ranch, Nick, stung by his uncle's harsh criticisms about his horse-racing abilities, becomes angered and forgets to put Tugfire back in his paddock. As a result, the horse is stranded in a rainstorm and falls critically ill. Although Nick blames himself, Jed forgives the boy for his mistake. Liz consoles the devastated Nick, who has become devoted to the horse. The two fall asleep during an all-night vigil at Tugfire's sickbed, and when Tugfire stands up and nuzzles Nick the next morning, Liz kisses Nick in delight. The day of the big race at the Bentonville fair arrives, and Jed, once again excited about racing, accompanies Tugfire and Nick. At the fair, Nick invites Liz to join him for a ride on the ferris wheel and they kiss. As Nick readies for the race, Joe appears with orders to send Nick back to Chicago for violating the court prohibition against driving, but Dan Templeton, Liz's father, convinces Joe to wait until after the race for Jed's sake. When Nick is knocked from his sulky during a qualifying heat, Jed decides that he is not ready to enter the finals, but Nick begs for the chance to prove his ability. After Jed relents, Nick proudly guides Tugfire to victory as Jed, tears of joy streaming down his face, cheers. When Joe delivers the bad news that Nick must return to Chicago because Fran's accident report stated that he was driving a car, Liz claims that the report was mistaken and that she was driving. After Fran, Al and Henrietta all support her story, Nick tells the truth, but Joe accepts Liz's version and drops all charges. The group then drives home, singing.