The Rio Grande country right after the Mexican War sets the scene for one young Texan's ordeal in the name of freedom. Joe Mitchell and his father Tom, planned to go to California with the profits of the sale of their eighty mustangs. But Joe fell asleep on watch and stealthy Indians stole the herd. Attempting to retrieve them Joe was taken captive by two Mexicans, ranchhands of Don Enrique, a wealthy Mexican rancher owner of Los Coronados, whose son was killed during the battle of Chapultapec. Joe agrees to a year's stint as shepherd under Don Enrique. With the capture of Lapidos, the wild stallion who tries to drown himself in captivity, Joe risks his whole future. He turns the horse loose. Don Enrique relents and all comes right. Action, period and characterization are credible and compelling.