When kindly old rancher Pop McGee is sentenced to hang for rustling cattle from Dawson, a newcomer in town, Pop protests his innocence, and his friend, storekeepeer Boots Annie, sends for her old chum U.S. Marshal Sandy Hopkins to investigate. Saloon owner Phil Randall has engineered the frame-up against Pop because Pop's ranch sits atop a fortune in silver. Pop owes back taxes on the ranch, and therefore, Randall plans to snap up the property at the tax sale. Upon receiving Annie's telegram, Sandy asks his partner, Marshal Nevada McKenzie, to join him. On the day before Pop's hanging, Nevada rides into town and is followed by Sandy, posing as an Indian trader. Suspicious of the newcomers, Randall instructs Hawkins, the corrupt sheriff whom he controls, to watch them. After Annie relates Pop's plight to Sandy, Sandy apprises Nevada of the situation. On the morning of the hanging, Nevada breaks Pop out of jail and hides him in an abandoned cabin. Upon returning to town, Nevada shows the blacksmith a horse shoe that he found in Pop's corral, and when the blacksmith identifies the shoe as belonging to Randall's horse, Nevada goes to the saloon to find Randall. After questioning Randall about his involvement with the rustlers, Nevada stalks out, passing Dawson in the doorway. When Dawson identifies Nevada as the lawmen who jailed him years earlier, Randall suggests that he bushwack the lawman in revenge. Dawson purchases several cartons of bullets from Annie's store, but Sandy uses a mirror to flash a warning to Nevada, and when Dawson bursts into Nevada's hotel room, he empties his pistol into a figure lying on the bed. Drawn by the sound of gunfire, Sandy and Hawkins run to the room and find Nevada lying on the floor. After Sandy pronounces Nevada dead, Hawkins leads his men in pursuit of Dawson. As soon as the sheriff departs, Nevada stands up, unhurt, and he and Sandy ride in search of Dawson, who has been double- crossed and shot by Randall. Spotting Dawson's horse roaming along the trail, the lawmen find Dawson, wounded and unconscious. Aware that Dawson can exonerate Pop, Sandy sends Nevada back to town with the wounded outlaw while he stalls Hawkins and his gang. When Hawkins finds Sandy with Dawson's horse, he arrests him as an accomplice and takes him back to town. Meanwhile, Randall has inspected Nevada's room and discovered that the marshal is still alive. When the sheriff tells Randall about Sandy's arrest, Randall provides him with an alibi. After Sandy is released, Randall instructs his men to follow him, thinking that he will lead them to Nevada and Dawson. Nevada, meanwhile, has hidden Dawson in Annie's back room and gone to look for a doctor. Upon returning to Annie's store, Sandy finds Dawson, and Dawson, knowing that Randall has betrayed him, confirms that Randall framed Pop in order to gain control of his silver-rich ranch. By the time Nevada returns with the doctor, Dawson is dead, however, forcing the lawmen to secure other evidence of Pop's innocence. While Nevada rides to search Dawson's ranch, Jim Bowen, a friend of Pop's, delivers some food to the fugitive. Jim is tailed by Randall's thugs, who take Pop and Jim prisoner. At Dawson's ranch, Nevada finds the branding irons used to frame Pop. Soon after, two of Randall's thugs surround the ranch, intending to ambush Nevada, but Sandy shoots one and drives the other away. Baxter, who escapes, warns Pop's captors that Nevada and Sandy are on their way, but the lawmen outsmart the outlaws, surround them and force them to surrender. After freeing Pop and Jim, Sandy and Nevada gallop back to town, arriving just in time to halt the sale of Pop's ranch. After Nevada declares that Randall and Hawkins are under arrest, Hawkins pulls his gun and Nevada shoots him. Their mission accomplished, Nevada and Sandy say goodbye and ride their separate ways.