Scott Jordan's mission in life is to train a wild stallion named Black Midnight.

Ranch owner Bill Jordan treats his nephew Scott as a surrogate for his black sheep son Daniel, who ran away from home years earlier. One day, Scott and Bill attend a party at the neighboring Baxter ranch to welcome home owner Martha and daughter Cindy. After Sheriff Gilbert presents Cindy with her late father's mare, Daniel appears, accompanied by his new friend Roy, several mares and a wild black stallion that he claims to have bought. Unable to break the stallion, Daniel is about to destroy the animal when Scott offers to buy the horse for thirty dollars. Naming the stallion Midnight, Scott exercises great patience and soon tames the horse. One day, while browsing through some hand bills, the sheriff notices one containing information about some stolen horses, prompting him to question the brand on Daniel's horses. To circumvent the sheriff's suspicions, Daniel orders Roy to get rid of Midnight. After being pummeled by Roy, the horse tramples his attacker to death. Fearing that Bill will shoot the animal, Scott hides Midnight in the hills, where he and Cindy treat the horse's wounds. Later, the sheriff convinces Bill that Roy provoked the horse's attack, and Bill finally wins back Scott's trust when he shoots a mountain lion that was threatening the boy and his stallion. To avoid being arrested as a horse thief, Daniel decides to kill the sheriff but is foiled by Midnight. After Daniel gives himself up, charges are dropped against him and he returns all the horses except Midnight, who is awarded to Scott.