When Boyd Matheson rides into Gradyville, Arizona, he discovers a town that lives in fear of a despot. Bull Grady founded the town, yet now demands that all business establishments pay him `rent'. Those who disobey risk death.
Grady has summoned Matheson, a hired gun, to kill the town's sheriff. When Matheson refuses, Grady has the sheriff murdered and Matheson framed for the crime. With help from those in the town who are opposing Bull Grady, Matheson escapes the rope but still finds himself in peril. The townfolk who rescued the gunman now want him to become their sheriff and help dispose of the tyrant.
An upcoming election for mayor turns Gradyville into a battleground as the new sheriff must risk his own life to ensure an honest outcome. But Bull Grady isn't Boyd Matheson's only enemy. A smoker since boyhood, cigarettes and even cigarette smoke thrust Matheson into terrible coughing fits. After a series of brutal encounters with Grady's henchmen, Matheson's chest tightens as he stands in Bull Grady's smoke-filled office for a final duel with the tyrant's fastest gun.