The night that Mack Lowman's mare foals, the barn is struck by lightning, killing Mack, but Danny, his seventeen-year-old son escapes with the colt, Gantry the Great. Midge Griner gets Danny a job on the horse farm owned by her father, Colonel Bob Griner. Danny trains and rides Gantry to fame, but the horse goes blind in the Kentucky Derby, as the favorite, and pulls up and loses. Through a misunderstanding Danny is banned for a year. To recoup his and Gantry's honor, he enters the blind horse in the Aintree Grand National Steeplechase in England.