The horse herds of rancher John Baker are being rustled by his neighbor, Mack Larkin who is working with Baker's foreman Bert. "Phantom" (the original "Starlight"), a wild stallion, is blamed for inducing the horses to run away. Baker puts a price on the head of the stallion. Wandering cowhand Tom Riley, with his sidekick Windy, feels the horse isn't to blame and talks Baker into giving him two days to capture and break the horse. Despite the handicaps thrown in his path by Larkin, Riley manages to capture "Phantom.". The horse leads him to a hidden valley where Larkin keeps the rustled stock. Aided by Windy and Bert, who has a change of heart, after learning that Larkin his been double-crossing him, Tom is able to capture the rustler and his gang, and "Phantom" is turned loose to resume his free ways.