Lucy Bostil, daughter of a Colorado ranch owner, is led by a dog to his master, Lin Slone, who is exhausted from a struggle to capture a wild horse; she revives Lin and they christen the horse "Wildfire." The Bostils have entered Sage King in a race, but Lucy agrees to tame and train the wild horse, since Buckles, her favorite colt, has been stolen. When Joel Creech, a half-witted stable hand, is discharged, he becomes a tool of the Cordtses--who also have entered a horse (Buckles) in the race--in drugging Sage King. Lin and Lucy enter Wildfire under the Bostil colors, and she rides him to victory, When Cordts is disgraced and discovered to be a horse thief, he persuades Joel to abduct Lucy. Joel does so, but first he kills Cordts. Warned by his dog of Lucy's danger, Lin pursues and rescues the girl.

Ce synopsis est en anglais : nous ne l'avons pas encore traduit.