Thoroughbreds.

Rusty Curtis of the U.S. Cavalry division is unhappy about the Army's plan to replace horses with tanks. Rusty tries to buy his old military mount, Sireson, but wealthy socialite Sally Crandall outbids him. Sally's father hires Rusty to train the horse for a big steeplechase race. A rivalry begins because Sally has a favorite horse of her own, but when hers is hurt, she and Rusty declare a truce.