Joel McCrea brings law and order to the range in Stranger on Horseback. McCrea portrays circuit judge Richard Thorne, who comes to a small western town in the course of making his rounds. There he finds the town and surrounding area under the feudal thumb of an oldline family headed by Josiah Bannerman (John McIntire). Despite wholehearted opposition and obstacles, Thorne fingers Bannerman's spoiled son, Tom (Kevin McCarthy) for murder and smokes out the necessary frightened witnesses and defies the whole clan by seeing that justice is done. In doing so he even wins the grudging respect of the old cattle baron, gains the love of the latter's strong-willed niece, Amy (Miroslava), and awakens the sheriff (Emile Meyer) to a new sense of duty.