Darrell, a cocaine dealer, sparks a desperate chase across the sun-scorched desert as a pursuing female cop closes in. She follows him until he hurls a brick of cocaine through the car window, and it bursts across her windshield. With the chase ending in a broken-down ride, he must straggle on foot and finds himself wandering into Sunset Valley—a town that materializes out of nowhere, its population sign seemingly stuck on 99. Inside the saloon, a Zombie Bartender launches a brutal assault, and he barely escapes into the street only to be stalked by legions of the undead until he meets Bloody Bill, who rips out his throat in a final act of ruthless aggression.
Meanwhile, a debate team—Gwen, Mandy, Sondra, Buck, Jerry and their coach Avery—journeys toward a tournament in Phoenix, only to be hijacked by Earl, Darrell’s hard-edged partner. Earl carjacks the van and heads toward Sunset Valley, now with the population sign climbing to 100. As they search empty storefronts and vacant rooms, a hostile, undead version of Darrell looms up and warns Earl that Bloody Bill is coming before he fully transforms and attacks Jerry, who is ultimately shot by Earl. Bill and his growing horde descend on the town, and Sondra flees on her own, bumping into a young girl zombie that leads her into a house where other zombies feast on human remains. Sondra is overwhelmed and slain; the population sign ticks up to 101.
With the town under siege, the group holes up in a house while Jerry explains the legend of Bloody Bill Anderson: a Confederate war-criminal who was hunted and hanged by Sunset Valley’s residents, but who allegedly gained supernatural powers through a deal with the Devil. They hear Sondra’s cries outside and rush to her, only to discover her mutilated body. Buck panics and runs in circles, Avery fights Earl, and the two of them wrestle the weapon away from Earl just as the zombies overwhelm the house. Mandy, Gwen and Jerry are separated, while Buck continues to circle back toward Sunset Valley. When Bill’s minions close in, Buck is crushed by Bill’s bare hands, and the population sign climbs to 102.
Inside another house, Mandy and Gwen discover a photo of Mary Anderson—who closely resembles Gwen—on the back of a note to Bill. Jerry’s grip on reality slips as he slides toward full zombification, and Gwen, Mandy and Earl learn that their friend’s fate is sealed. Avery reenters the fray just in time to be stabbed by Bloody Bill, and his zombies flood the room. The four survivors retreat upstairs and barricade themselves with furniture as Jerry finally becomes one of the undead and turns on Earl. Gwen shoots both Jerry and Earl, knowing the latter will inevitably zombify, and makes a split-second choice to stay behind while the others flee. Earl detonates a last-ditch grenade, the blast throwing Bill’s zombies back and silencing the room as the population sign edges to 106—an inexplicable spike for a few additional losses.
Mandy and Gwen surface to a town that now seems haunted by a cruel trick of fate. They confront Earl, who has somehow donned Bill’s clothes and wields his rapier. In a gruesome reveal, Earl’s own face peels away to show Bill beneath the disguise. The impostor malforms into a chilling specter, and Bill gives chase to Gwen toward the church, where a shrine to Mary stands as a grim reminder of the town’s horrific past. Gwen manages to seize Bill’s rapier, uses it to decapitate Bloody Bill, and in doing so, destroys his remaining zombies. As she staggers toward the exit, the population sign again leaps, this time to 107, signaling the town’s tragic tally of victims and the eerie persistence of Sunset Valley.
