In Pecos, Texas, newspaperman Carson is painting a sign outside his office, alerting citizens to the land-grabbing tactics of Martin Conroy, when he is attacked by three of Conroy's thugs, Garrett, Foster and Higgins. As the thugs rough up Carson and wreck his printing press, cowboys Tim Holt and Chito Rafferty ride into town and hear his screams. Tim and Chito stop the fight with their fists and guns, then send the henchmen on their way. After a grateful Carson explains that Conroy has been using extortion and theft to acquire land for the railroad and controls all communications in Pecos, Tim and Chito offer to go to nearby Red Bluff and send a telegram to Terry Moran, the marshal who cleaned up El Paso. On the way, Garrett, Foster and Higgins attempt to ambush the cowboys, but Tim has anticipated the attack and eludes them. Tim and Chito then stop at a ranch owned by Bailey, the man who originally summoned them to Pecos. Bailey reveals that he rejected Conroy's low bid for his ranch and now fears that Conroy will resort to strongarm tactics to get what he wants. After Tim and Chito promise to protect their old friend, they resume their journey to Red Bluff, but soon are waylaid by Conroy's men. As Tim has memorized Carson's wire, the thugs find no evidence that he and Chito are anything but out-of-work cowboys and release them. Later, word comes that Moran is about to arrive in Pecos, and Conroy and his men set off to ambush the stage. Carson alerts Tim and Chito to Conroy's plot, and the cowboys race to intercept the thugs. While hiding among some rocks, Conroy and his men shoot one of the stage's drivers before Tim and Chito ride up and chase them off. To Tim and Chito's surprise, the coach's only passenger is a woman. After delivering the woman, who identifies herself as Terry Moran, the lawman's daughter, Tim returns to investigate the scene of the ambush and there finds shell casings and a piece of a gun handle. Back in Pecos, Terry explains to an irate Carson that her father has been hospitalized and she needs the marshal job to earn money to pay his medical expenses. Carson refuses to hire a "petticoat marshal" until the determined Terry shows off her shooting skills and asks Tim and Chito to be her deputies. Now anxious to finish his business in Pecos, Conroy instructs Garrett to offer Bailey $15,000 for his land but only give him $1,500 in cash. Bailey falls for Conroy's trick, not realizing until he has already signed the bill of sale that he has been cheated out of $13,500. Later, after they have searched Conroy's office for a gun with a broken handle, Tim and Chito arrive at Bailey's and learn about the land sale. Bailey is furious at the cowboys for not protecting him and dismisses them. Seeing no other recourse, Tim sets off for El Paso to see Latimer, the unsuspecting railroad man with whom Conroy is dealing. Five days later, Conroy and his henchmen go to Bailey's to take possession of his ranch, but Bailey refuses to leave and starts a gunfight. Conroy sends Garrett for the marshal, just as Tim returns to town with news that an angry Latimer is on his way to Pecos. Tim, Chito and Terry then disarm Bailey and jail him for his own protection. Later, at Conroy's office, Tim and Chito catch Garrett cleaning his gun and discover that he has just replaced the handle. Matching the discarded handle with the piece he found among the rocks, Tim concludes that Garrett is the sniper and arrests him. Conroy, however, breaks Garrett out, knocking Chito unconscious and locking Terry in the cell. Terry manages to free herself and locates Tim. Together they rescue Bailey and Carson, who were on their way to meet Latimer, from an attack by Conroy and his men. Tim shoots and kills Conroy, then nabs the fleeing Garrett. After Terry secures all of Conroy's illegally obtained land deeds, she and Tim return to the jail and revive the still-unconscious Chito.