When Texas ranger Jim Madden hears that his younger brother Larry, a new recruit, has been ordered to investigate a case involving the brutal murder of a rich rancher, he asks his boss to give him the dangerous assignment instead. Eager to prove himself, naive Larry explodes with anger as Jim rides off to track down the suspected killer, cattle rancher Joan Stanton. That night, however, Larry discovers Jim's bullet-riddled body and swears revenge on Stanton. In town, Larry learns that wealthy rancher Frank Sanderson is offering a reward for the capture of Joan and rides to Sanderson's hacienda fortress to investigate. As he arrives, he sees Joan and her men running off a group of Sanderson's cattle and then follows her into the rancher's heavily guarded sanctuary. After accusing Sanderson of killing her father and stealing her cattle, Joan robs him of his cash supply. While escaping, she is cornered by Sanderson's men but is rescued by Larry, who is wounded in the process. Grateful for Larry's bravery, Joan takes him to her hidden valley hideout and nurses him. Larry, still unsure of Joan's innocence, hides his Ranger badge and begins to question her about Sanderson. After she tells him that Sanderson has been framing her, Larry convinces her to turn herself in to the Rangers. On their way back, however, they are pursued by both Sanderson's and her own men, who have found Larry's badge. Cornered, Larry turns Joan over to Sanderson and demands his reward money, but that night, Sanderson orders one of his men to kill Larry and take Joan over the Mexican border. Before he can execute the plan, however, Larry and Rusty, the Ranger's cook, fight with Sanderson and, with the help of Joan's men, defeat the murderers. Larry then rides back to the valley with Joan.