The Dead Girls are a death metal group consisting of Gina, Dana, Amy, Susie, and their male drummer Mark. Their manager, Arty, is determined to push the band toward a mainstream direction, but the group resists, knowing that their appeal lies in on-stage shock value, violent spectacles, and morbid lyrics; only Mark, the Juilliard-trained member, provides real musical backbone.
Gina's teenage sister Brooke, along with other devoted fans, acts out a mass-suicide bid that Brooke survives. Gina returns to her hometown amid the funerals and reconnects with her childhood friend, Mike. The family’s conservative aunt Aunt Annie and uncle Uncle Jim blame the band for inspiring Brooke’s distress. In response, the band agrees to a two-week retreat at a remote cabin so Gina can recover, bringing Brooke along despite the aunt and uncle’s reluctance, along with their assistant Jeff and a nurse who oversees Brooke’s recovery. Just before they depart, the manager is murdered in his office by a skull-masked killer.
Upon arrival at the cabin, the group is greeted by Elmo, a developmentally-disabled handyman who maintains the property. Mark covertly brings a female groupie to the cabin, but the others force her to leave after finding him with her. While wandering in the woods, the groupie is murdered by the masked killer. The next day, Susie is attacked and drowned in the lake, and Gina discovers her body. She phones the police, but Susie’s body disappears and the sheriff, Sheriff, suspects the band is pulling a stunt. Amy suspects that Susie is pulling a prank, as she has regularly performed fake deaths during the band’s live concerts.
In the morning, Jeff goes missing, and Gina and Amy discover Susie and Jeff’s corpses in a barn on the property. Gina flees, trying to stop the nurse from departing in the group’s van to take Brooke to the hospital; however, the nurse leaves with Brooke, stranding the group. The phone lines have been cut, and the group starts turning on each other, with Dana accusing Gina and Amy of being responsible for the killings.
Amy, a military combat enthusiast, sets traps in the barn, hoping to catch the killer. Meanwhile, Dana reconciles with Gina and presents evidence suggesting that Mark is the killer. Amy is attacked in the woods by the killer and dismembered with an axe. When Mark returns to the cabin with firewood, Gina tries to leave, only to stumble upon Amy’s corpse. Back at the cabin, Gina finds Dana bound and gagged, and is confronted by Mark, who wields a pistol. Gina shoots Mark, ending his threat, and Dana reveals that she and Mark had plotted to murder Gina and Amy, fearing they were complicit in the killings. Before Dana can retaliate, the masked killer appears and slashes her throat.
Gina flees into the woods as the killer closes in. Elmo appears, and Gina thinks he is the killer. Moments later, Mike arrives and bludgeons Elmo to death. Mike reveals that he is the true murderer, driven by extreme religious beliefs and the conviction that the band promotes evil. He binds and gaggs Gina in the barn, which is now filled with all his victims’ corpses, but a misstep trips the potassium nitrate bomb that kills him.
The nurse returns with Brooke, suspecting the band has left without warning. While Brooke waits in the van, the nurse discovers Gina bound and gagged in the barn. Disgusted by what has happened and believing the group has indulged in a sadistic game that led to the killings, the nurse chooses to depart with Brooke, leaving Gina to die in the barn.
