Ronald Sinclair "Roger" and his aristocratic - but poor - grandfather "Sir Peter" (C. Aubrey Smith) travel to the United states with their horse "The Pookah" hoping to race it and reverse their declining fortunes. They decide to enlist the services of young jockey "Donovan" (Mickey Rooney) who is lodging with the feisty "Mother Ralph" (Sophie Tucker) and "Cricket" (Judy Garland). After a particularly rocky start, the two boys and the elderly gent look set to clean up... That's before they reckon on the jockey's crooked father, who pretends to be critically ill so his son, secretly, will throw t...