Warlock is a Western, named after the fictional town in which it takes place. In 1881, the town is just beyond the edge of civilization, a day's ride from the nearest sheriff and courthouse. The Apaches have been subdued, but gangs of cattle rustlers still wreak havoc. The chamber of commerce hires a famous gunslinger as marshal to keep the peace.
The story features all the archetypes of a Western: gunfighters, deputies, rustlers, miners, whores, business tycoons, frightened townsfolk. The action is based on historical events such as the gunfight at the OK Corral and the Lincoln County War. The author's purpose is to show how these legends form.
The characters carefully consider their actions, balancing the demands of their conscience, their job responsibilities, social expectations, and their reputation in posterity. The town council orders the marshal to throw four troublemakers out of town, three men who robbed the stagecoach and a union organizer from the local mine. How can the marshal justify "posting" the three thieves but not the union man? He has been hired to enforce the will of the town council not the law (he is a marshal not a sheriff). If he enforces rules based on no higher authority than his conscience, is he any more than a tyrant?
The best and most distinctive aspect of Warlock is its careful consideration of its characters' ethical dilemmas. That's also what slows the story down between its big action sequences. There are longueurs before and after each major event, with each character evaluating the consequences.
One of the major events in the book is a strike at the Medusa mine. I don't feel like this plot thread got the full attention it deserved.