Sir Peter Calverton takes his horse "The Pookah" to California to run in the Santa Anita Cup race in the hope of winning enough money to save his financially strapped estate. His grandson Roger and their trainer Wilkins also go along and convince Sir Peter to hire jockey Timmie Donovan. Donovan, though a brilliant jockey, has a reputation for having a "swelled head." He lives at Mother Ralph's boardinghouse along with her niece, Cricket West, and several other jockeys. Timmie and Roger develop a strong friendship as they prepare for the race, and it is only at Roger's urging that Timmie goes to see his estranged father. "Click" Donovan abandoned Timmie as a boy, but now begs him to throw a pre-Cup race so that his friends can win enough to pay for his expensive medical bills. Timmie is reluctant, but finally agrees and throws the race. When The Pookah loses, Sir Peter has a heart attack and dies. Timmie is so remorseful that he disappears, but when he discovers that his father's "illness" is all a ruse, he takes some of the winnings to pay for The Pookah's entrace fees in the Cup race. Click meanwhile arranges for track officials to learn about Timmie's crime. Timmie admits his guilt, exonerating Sir Peter and Roger, but is banned from racing. With Mother Ralph's help, however, Roger is able to qualify and he rides The Pookah to victory. Now financially solvent, Timmie, Roger, Cricket, Wilkins and Mother Ralph are able to ride from racetrack to racetrack in comfort.