School teacher Virginia King, annoyed by the unwanted attentions from Mesa City sheriff Jud Cronin, resigns and departs for Yuma. Her stagecoach is attacked by a gang led be Cronin's henchman Pete Henderson, trying to force her to return to Mesa City. Ex-lawman Cliff Mason comes along and disarms and unmasks the outlaws. It will take several days to repair the coach and Cliff takes Virginia back to Mesa City. Cliff identifies the outlaws, but Marshal Andy Thompson is killed trying to arrest Henderson, who makes a getaway. Mayor Sam Bentley appoints Cliff marshal pro tem. Cliff arrests the outlaws but Judge Wainwright is on Cronin's payroll and sets them free. Cliff persuades the city council to pass a law forbidding the carrying of firearms by others than officers of the law. Cronin sends for Duke Allison, notorious gunman, to deal with Cliff, but Cliff saves Duke's life and Duke accepts a deputy marshal's badge from Cliff. Cronin arrests Cliff and Duke for the killing of Henderson, and then sets fire to the jail they are in.