Dr. Sam Martin, a well-respected physician in the small Western town of Prairie Dog, is engaged to marry Hannah Brockway, the daughter of Nathan Brockway, an insurance adjuster. In addition to his responsibilities as a doctor, Sam is often called upon to keep the peace in the rough town, as he is one of the quickest gunmen in the region. One day, while returning from a stagecoach trip to Denver, Hannah and her father Nathan are held up by outlaws Cash and Frank Dembrow and their father Kirk. The Dembrow gang's scheme is foiled, however, by the arrival of a mysterious rider, who scares off the thieves and later introduces himself to Hannah as Ben Taylor. Ben, who is actually another one of Kirk's sons, safely escorts the Brockways back to Prairie Dog. After being hailed as a hero by the townspeople, Ben asks Sam to pay a house call on his mother Sarah, who lives in a shack near town and is suffering from a mysterious illness. Sam agrees to examine Sarah, and later concludes that her illness is a result of a traumatic event in her past. Sam asks Ben to tell him about his mother, but Ben refuses to discuss his family's past. When Sam sees Ben shoot a snake with extraordinary speed and skill, he asks Ben how it was possible for the Dembrow bandits to have escaped him. Ben eventually confesses to Sam and Hannah that he is a Dembrow, but he insists that he is opposed to his family's thieving and is determined to live a law-abiding life. Meanwhile, Ben's father and brothers continue terrorizing the people of Prairie Dog by holding Nathan hostage in his own home and attempting to rob him. Their plan fails, however, when Nathan's cries alert some of the townspeople. The Dembrows leave Prairie Dog in haste, and a posse is formed to capture them. The outlaws manage to elude capture, however, and later take refuge at Sarah's home. Ben, determined to keep things peaceful while Sam finishes treating Sarah, forces his father and brothers to leave. A short time later, the sheriff and the posse arrive at Sarah's with news about the holdup of Hannah's father. When the sheriff arrests Ben simply because he is a Dembrow, Sam persuades Ben to go willingly, assuring him that the arrest will provide him with an opportunity to clear his name in court. While Ben awaits trial in his jail cell, Hannah visits him frequently and a secret romance between them ensues. Sam presents a powerful defense at Ben's trial, but while the jury deliberates Ben's fate, the Dembrows burst into the courtroom with guns drawn and spirit Ben away. Ben, believing he has little chance of being vindicated by the jury, joins his father and brothers and resumes his participation in their criminal exploits. Hannah runs away with the Dembrows and marries Ben, but when she discovers that she is pregnant, she decides to break free of the family. Hannah sends word to Sam of her whereabouts through an itinerant alcoholic named The Alkali Kid, and Sam rescues Hannah from the Dembrows and takes her back to Prairie Dog. After Hannah gives birth to a baby boy, Ben finds her and makes a failed attempt to persuade her to return to him. He then steals the baby and takes him to the Dembrow hideout. Sam eventually finds the Dembrows and kills Kirk and Ben in a shootout. With her baby safely returned, Hannah finally agrees to marry to man who is meant for her.