U.S. Cavalry Sergeant Rusty Curtis, stationed at Camp Ralston, adores horses and refuses to believe rumors that the Army intends to replace its horses with tanks. While on medical leave for an injury sustained during a training session, Curtis learns that the rumors of mechanization are true, and that orders have been given to sell the camp's horses at an auction. After making an impassioned but failed attempt to prevent the removal of his favorite horse, Sireson, Curtis is given a medical discharge and returns to civilian life. A short time later, Curtis tries to buy Sireson at a horse auction, but socialite Sally Crandall, the fiance of his former barracks mate, Jack Martin, outbids him. Although a feeling of mutual animosity grows between Curtis and Sally following the sale of Sireson, Sally's father John becomes friends with Curtis and hires him to train the horse for the Brookside steeplechase. John also offers Curtis a one-half financial interest in the horse. Sally, meanwhile, begins training her horse, Princess, to beat Curtis in the competition. The rivalry between Sally and Curtis continues until Sally's horse takes a fall and is disqualified from the race. A romance soon develops between Curtis and Sally as they work together to train Sireson. Just before the big race, Jack, home on a furlough, overhears gangster Harold Matthews offer Curtis money to throw the race. Curtis refuses the bribe, but Jack leaves before he hears Curtis' response. Jack's suspicions of Curtis are further raised when it is discovered that someone had been tampering with the trailer used to transport Sireson. Convinced that Curtis' motives are impure, Jack insists on riding the horse himself. Curtis, however, refuses to allow Jack to ride Sireson, and throws a punch at him to prevent him from taking the reins by force. Curtis then mounts Sireson and rides him to an easy win. After the race, Jack offers Curtis his apology, and, realizing that Curtis and Sally are in love, gives his blessing to their romance.