After the outbreak of the Civil War, Kentucky Carson rescues a little boy named Danny when he is kidnapped by an Indian who killed his parents. After bandits rob a stagecoach of gold intended to pay cattlemen, Carson brings the runaway stage into town. Nick Slavin, a prominent man about town, arouses suspicion about Carson because of his frequent disappearances. Stagecoach owner Joe vows to send to Washington for help in rounding up the thieves. After he is found dead, the Poncho Riders, a self-appointed posse who wear Mexican ponchos and are secretly led by Carson, capture Red, Joe's probable killer. Carson himself is caught by Huston, the sheriff, who operates under Slavin's rule, but Carson escapes. Postmaster Cameron, who has unofficially adopted Danny and his dog Sagebrush, has been involved in the stagecoach robberies with Slavin. At heart an honest man, Cameron tells Slavin he is backing out. Slavin tries to have him killed, but Cameron instead kills his assailant. Slavin then tries to force Danny, a witness to the murder, to tell what happened, but Danny refuses, even after Slavin apparently has Huston kill Sagebrush. Cameron confesses, however, and incriminates Slavin in the robberies. The Poncho Riders convince Huston, who has been an ineffectual sheriff, to join them after showing him their commission from Abraham Lincoln. They rescue Cameron from being hanged and capture Slavin, who then kills himself. Carson refrains from arresting Cameron because he believes in his goodness, and Huston returns Sagebrush unharmed to Danny.