Warlock unfolds in a small, rough Utah mining town in the early 1880s, an unincorporated place where Abe McQuown's cowboys roam freely, killing at whim and driving out deputies who try to enforce order. To restore some stability, the town hires Clay Blaisedell, a renowned gunfighter, to serve as marshal, despite the initial skepticism of locals like Judge Holloway.
With him arrives his devoted, clubfooted friend Tom Morgan, a first-rate gunman and heavy-drinker who also runs the town's saloon. Morgan’s presence confirms that the two men will be a package deal, something Blaisedell accepts as he tries to bring order to a place where law feels optional.
The stagecoach soon carries Lily Dollar into town, accompanied by Bob Nicholson, brother to the recently killed Big Ben Nicholson. Lily has a painful history with Morgan: she left him for Ben, and now she wants Blaisedell dead to punish Morgan. She learns that Morgan has returned, adding personal tension to the town’s already fragile balance.
From a distance, Morgan spots a stagecoach robbery in progress and uses the opportunity to silently kill Bob Nicholson, a deed Lily will rightly deduce she witnessed. The robbers are arrested by Clay Blaisedell and a posse, but the sheriff—who distrusts Blaisedell’s methods—invites Johnny Gannon to serve as Warlock’s deputy, shifting the town’s power dynamics.
The criminals, led by Abe’s men, are brought to Bright City for trial, yet the jury is intimidated and clears them. The cowboys, led by Billy Gannon, surge back into the streets in anger. A tense street confrontation follows. When a cowboy tries to shoot Blaisedell in the back, Morgan spots him and fires, killing two, including Billy, while Blaisedell shoots the others. The regulators earn mockery from Curley Burne Curley Burne, who casts them as quasi-legal figures. Johnny Gannon vows to stop any regulators who come to town, and Curley ends up stabbing him in the gun hand, raising the stakes for everyone.
Tensions rise as the townspeople begin to resent Blaisedell and Morgan, even as Blaisedell starts a romance with Jessie Marlow Jessie Marlow and contemplates marriage. Morgan, meanwhile, worries that the bond between Blaisedell and Lily may fracture his own chances to move on.
Despite a wounded hand, Gannon faces the cowboys with resolve, aided by the people and Curley Burne. He and Blaisedell clash with the outlaws, and McQuown is killed, ending the regulator threat for good. Morgan resents Gannon’s rising hero status and Lily’s attraction to the deputy, and in a heated exchange, Blaisedell learns the truth about the Nicholson brothers’ deaths and turns away from Morgan.
In a drunken, bitter confrontation, Morgan challenges Gannon, prompting Blaisedell to lock Gannon in his cell, declaring, “Tom Morgan's my responsibility.” Initially cowed, Morgan is emboldened as townsfolk jeer, and he taunts Blaisedell into a showdown. Morgan shoots off Blaisedell’s hat and is fatally wounded moments later. His dying line lands with brutal bluntness: > "I won, Clay, I won!"
Grief-stricken, Blaisedell carries Morgan’s body into the saloon and burns it. Gannon warns Blaisedell that he will arrest him in the morning if he stays, and Blaisedell decides to leave town. Jessie refuses to accompany him. The next day, the two men face off again: Blaisedell outdraws Gannon, then theatrically throws his golden-handled revolvers into the sand, smiles at Gannon, and rides off, choosing solitude after a hard-won victory.
