The film starts, Bailey challenges her college roommate Harper to definitively break up with Harper's abusive boyfriend Sam. Accompanied by their other roommates Angela and Mallory, Harper and Bailey then attend a Halloween party where they meet up with attractive jock Nathan and his loudmouth friend Evan.Evan, Nathan, Harper, Bailey, Angela, and Mallory drive to a remote location to visit an extreme haunted house operated by people wearing Clown, Ghost, Witch, Vampire, Devil, and Zombie masks. Inside the attraction, the six friends witness the Witch torturing a captive woman in a milieu that appears real.At a fork in the maze, Evan, Mallory, and Harper go in one direction while Bailey, Nathan, and Angela go in another. Bailey, Nathan, and Angela encounter a test of courage that severely injures Bailey's hand and causes her to lose the heirloom ring she borrowed from Harper.Evan and Harper lose Mallory in a series of pathways that force them to go through separately. A hooded man compels Evan and Harper to continue forward without Mallory. Evan and Harper briefly encounter the Zombie wielding a chainsaw.Evan and Harper rejoin Bailey, Nathan, and Angela, but become locked in the same room. From the other side of a fence, the five friends helplessly watch the Witch seemingly kill Mallory.Confused and desperate for help, Nathan moves on alone until he encounters the masked Ghost, who identifies himself as Mitch. Mitch cagily promises to help Nathan and his friends.Bailey apologizes to Harper for losing her mother's ring. Harper confides in Bailey about growing up with a father who physically abused her mother. Meanwhile, Angela injures her hand while trying to obtain a crowbar for Evan.Nathan returns with Mitch, who claims everything is merely part of the show and no one was meant to get hurt. Mitch unlocks the door so everyone can backtrack. However, they discover the emergency exit leads to a brick wall.The group decides to go back through the single-file tunnel. Evan goes first and returns to the maze. Mitch follows next, but boards up the tunnel so that Nathan gets stuck.The Devil enters the hallway where the three girls are waiting. The Devil puts his pitchfork through Angela's head. Bailey escapes into the tunnel. Harper retreats through the door that the Devil opened.The Devil confronts Harper, who thinks the masked man may be Sam tormenting her. The Devil unmasks to reveal a deformed face adorned with tattoos and body modifications. Nathan rescues Harper by firing at the Devil with a nail gun. Harper flees.The Clown uses Harper's confiscated phone to accept a call from Sam. The Clown vaguely taunts Sam.Mitch confronts Evan in the maze. Mitch unmasks to reveal his true face before killing Evan.Nathan recovers the ring Bailey dropped. Mitch confronts Nathan. Nathan manages to text his location to Sam on Harper's phone before fleeing.Harper encounters a series of traps that mutilate her body before she makes it into an escape room. Harper hides under the bed after solving the room's riddles. Hiding triggers a flashback to watching her father beat her mother as a child, which gives Harper the strength to fight back against the Devil. Harper attacks the Devil and unlocks the exit door, which triggers a shotgun trap. The Devil recovers and attacks Harper, but she maneuvers him into the gun's line of fire and he dies. Harper stabs another masked man with a pitchfork, but he turns out to be Bailey bound, gagged, and forced into a costume.Sam arrives at the haunt. Sam triggers a trap that fires a bolt into his throat. The Clown then crushes Sam's hand with a cinder block and smashes his head with a sledgehammer.Nathan regroups with Harper. Mitch attacks Nathan while Harper battles the chainsaw Zombie. Harper manages to shoot the Zombie and rescue Nathan from Mitch.Unmasking himself as a normal person, the Vampire surrenders to Nathan and Harper while claiming he didn't know the other actors were deformed murderers. One of the killers shoots the Vampire.Harper and Nathan kill the Witch by repeatedly slamming her head with a hatch door. Harper and Nathan escape outside where Nathan kills the deformed Zombie with a baseball bat after taking a bullet. The Clown sets fire to the haunt while Harper and Nathan eventually recover in a hospital.Some time later, the Clown breaks into Harper's parents' house. However, the Clown ends up caught in a trap as Harper fires at him with a shotgun.