Rascally cowboy Hewey Calloway is heading north to Colorado, on a horse drive for an old friend, when he gets word that one of his hired hands is planning to rob him. After the plot is foiled, the fugitive horsehand is on the run and leaving bodies in his wake. Hewey, the worst pistol shot in the West, is deputized to bring the criminal to justice, bestowing him with a weight of responsibility he's long avoided, and leaving him to wonder if even the help of a retired Texas Ranger is enough to put an end to this trail of dastardly deeds.