At Cooper's Diner, Mike Bramford, Steve Benson, and Bobby plot to haze mentally handicapped misfit Jacob Atkins as part of a longstanding Halloween tradition. Steve's girlfriend Carol Saperstein unsuccessfully tries dissuading the trio from hurting Jacob. Diner employee Gus insists on joining the prank.Jacob bikes to his new job at the traveling carnival Dr. Death's Sideshow Spookhouse Spectacular. Lester, the diminutive ringmaster who plays Dr. Death, chides Jacob for being late.Carol passively observes as Mike, Steve, Bobby, and Gus corner Jacob at the carnival. When Jacob fights back, the four bullies become more aggressive and end up beating Jacob to death.Lester finds Jacob's bloody body. Using occult magic and a Halloween mask, Lester resurrects Jacob as a supernatural creature of vengeance.The next day, Mike's father Sheriff Sam Bramford briefly spots Jacob covered in blood while out on patrol. Dispatcher Marcy Taylor calls Sam back to the Grove Hill sheriff's station when Carol arrives to tearfully explain what happened the previous evening. Mike later threatens Carol when he discovers she told his father what they did to Jacob.Sam goes to the carnival to investigate Carol's concern that her friends may have accidentally killed Jacob. Lester assures Sam that Jacob is fine despite his beating while also insulting Sam as a local authority figure.Jacob murders Gus in the bathroom at Cooper's Diner. Sam investigates the crime scene with Deputy Conrad and Deputy Fox. Steve and Carol also show up at the diner when they receive word of Gus' death, but Sam assures them the murder isn't related to the incident at the carnival.Mike, Bobby, Steve, and Carol meet to discuss a possible connection between Gus' death and what they did to Jacob. Mike blows off the suspicions. After everyone else leaves, Jacob appears and rips out Bobby's spine.Sam and Deputy Fox try to interview Lester again, but Lester dodges Sam's questions. Deputy Conrad interrupts to report Bobby's murder. Upon examining the new crime scene, Sam orders Marcy to issue a curfew while Conrad locks down the town.Sam asks his son if he has any more information about Jacob or the carnival. Mike cagily avoids his father's questions.Sam and Fox search Jacob's home. They discover the shriveled corpse of Jacob's mother hidden under a bed.Bishop Gate and the other carnies confront Lester for the truth about his occultism. Lester claims he is immortal while rallying everyone to combat the town's impending witch-hunt.Jacob murders Steve inside a movie theater in front of Carol. Jacob then pulls out Carol's tongue and she drops dead. Jacob suddenly collapses. Lester finds Jacob unconscious and has him brought back to the carnival to be revived with fresh blood.Sam and Fox discover the bodies at the theater. Sam immediately calls Mike to warn him that his friends are dead.Mike goes to the carnival to angrily confront Lester. Carnies capture Mike and force him to watch a bizarre stage performance.Sam goes home looking for Mike to find Lester waiting for him. Bishop Gate knocks Sam unconscious. Lester saws off Sam's head.After recovering from his capture, Mike stumbles into the carnival midway. The sheriff's patrol car pulls up with Sam's severed head adorning the hood.Jacob attacks Mike and rips off his arms. Lester gives Jacob a trick-or-treat pail of candy corn. Jacob pulls out Mike's teeth and replaces them with the candy.Lester brings his sideshow to Plainfield, Wisconsin where he sells a necklace made from Mike's teeth to a patron. Lester cryptically explains that he will always exact vengeance whenever the outside world tries to keep freaks like them down.