The Million Dollar Handicap.

After buying the filly Dixie following a strong finish Southern horse breeder John Porter discovers she has been doped for the contest. When he is paralyzed from a fall from Dixie his son, Alan, embezzles money from the bank to save the family finances. Because of his love for Alan's sister Alis, George Mortimer takes the blame for the crime, losing his job. Disguised as a boy, Alis enters Dixie in a race and rides the horse to victory and all ends happily.