Clark and Donovan are ordered to capture the mysterious Montague brothers, who are preying on Pony Express riders. There biggest problem: no one has ever been able to supply a proper description of the robbers.
Curious as to why a gorgeous Southern belle would travel all the way from Louisiana to Julesburg to meet Kit Dennison, one of his young riders, Clark searches for back issues of the New Orleans paper and learns that if Dennison is dead the débutante will inherit his uncles considerable estate.
Clark is knocked out and his horse stolen by a pretty blonde whom he had stopped to help along the road. When he fails to file on land the Pony Express wants to use for a station, the blonde and her partner in crime buy the parcel for a fraction of its value. The furious agent sets about recovering the land and his horse and learns that the key to both endeavors may be a saloon girl with a newborn baby.