Orphaned after the death of his father, ten-year old Tim Taggert goes to live on the ranch owned by his uncle Dave and aunt Ellen Taggert. Through the kindness of his new family, Tim transforms from a shy, sullen lad into a happy boy who delightedly takes part in ranch life. Although he is afraid to ride a horse, Tim looks forward to meeting King, a beautiful, wild stallion about whom his father, Danny, often spoke. Tim knows that Danny once nursed King back to health after the animal was seriously wounded by gunshot, and once King had regained his strength, Danny turned the horse loose and then abruptly left the ranch for good. A bad draught hits the territory, and one night, King, leading a band of wild horses, visits the ranch in search of water. Sensing that the animals are in distress, Tim pumps water for them, and as a strong bond develops between him and King, Tim discovers that he is no longer afraid of horses. When King and the herd return to the ranch for water and accidentally trample a fence erected as a cattle corral, Dave becomes furious and sets out to round up the wild herd and drive them into the corral. Like his father, Tim is unable to stand the thought of wild horses being held in captivity and so sets them free, thus incurring his uncle's wrath. After Dave orders Tim to his room, Ellen reminds her husband that Danny left the ranch because of an argument with Dave over freeing King and begs her husband not to repeat his mistake. When Dave goes to Tim's room to apologize, he discovers that the boy has run away. Tim, who has gone to look for King, finds the horse nursing a colt weakened by thirst. After Tim gives the colt water from his own canteen, Dave and his men arrive and take the boy and the two horses back to the ranch. There, Dave gives King a long drink of water and then sets him free. Dave and Tim nurse the colt back to health, thus repairing the rift between them. When Tim offers the little horse his freedom, the animal refuses to leave the ranch, preferring to stay by Tim's side.