The horse and a dog Lightning share the same birthday. Both are born in captivity, but end up escaping to the wilderness where they become close friends. When wolves attack a herd of wild horses, Lightning and Warrior team up to save them. When they return to domesticity, Warrior is trained to race by the Bentons. George Mason, a wicked gambler, attempts to stop Warrior from winning. However, Lightning tries to prevent the activities of Mason and his henchman Crane.