Following the events of the night before, a badly injured and unmasked Jason Voorhees goes to a lakefront store for a change of clothes. While there, he murders the store owners. Harold is killed with a meat cleaver slammed into his chest, and his wife Edna is impaled through the back of the head with a knitting needle. Meanwhile, Chris Higgins and her friends travel to Higgins Haven, her old home on Crystal Lake, to spend the weekend. The gang includes pregnant Debbie, her boyfriend Andy, prankster Shelly, his blind date Vera (who does not reciprocate his feelings) and stoners Chuck and Chili. After running into a man named Abel, who warns them to turn back, the gang meets Chris’ boyfriend Rick at their destination.
At a convenience store, Shelly and Vera get into a confrontation with bikers Ali, Fox, and Loco. Shelly gets in the car and knocks down their motorcycles, impressing Vera. Later, the bikers show up at Higgins Haven, where they take the gas out of the van and attempt to burn the barn down to get even. Jason, who has been hiding in the barn, murders Fox and Loco with a pitchfork before beating Ali unconscious. That night, Chris and Rick head out into the woods. Chris tells Rick the main reason she returned is to confront her fears, and she explains about how she was attacked by a deformed man two years earlier, causing her to leave Crystal Lake in order to escape the trauma.
Back at Higgins Haven, Shelly scares Vera with a hockey mask and then wanders into the barn, where Jason slashes his throat. Taking his mask to conceal his face, Jason proceeds to murder the rest of the group. Vera retrieves Shelly’s wallet from under the dock and is shot in the eye with a speargun. Jason enters the house and bisects a hand-standing Andy with a machete. Debbie finishes her shower and rests on a hammock, where Jason thrusts a knife through her chest from beneath, killing her. When the power goes out in the house, Chuck goes downstairs to the basement only for Jason to hurl him into the fuse box, electrocuting him. Chili finds that everyone else is dead and is then impaled with a hot fire poker.
When Rick’s car dies, Chris and Rick are forced to walk back to the house to find it in disarray. Rick steps outside to search the grounds, but Jason grabs him and crushes his skull with his bare hands, making one of his eyes pop out of its socket. Jason then attacks Chris, who narrowly escapes the house and tries to flee in her van. The van runs out of gas and Chris makes her way to the barn to hide, but Jason attacks her again. Inside the barn, Chris strikes Jason over the head with a shovel, and hangs him. He regains consciousness and unmasks himself temporarily to show Chris he is the man who attacked her two years ago. A revived Ali tries to attack Jason, but he is quickly dispatched. The distraction allows Chris to strike Jason in the head with an axe. Jason staggers momentarily towards her before finally collapsing. Exhausted, Chris pushes a canoe out into the lake and falls asleep.
Chris has a nightmare of an unmasked Jason running towards her from the house before disappearing, which then turns into the decomposing body of Pamela Voorhees, with her head attached, emerging from the lake to pull her in. The following morning, the police arrive and escort a traumatized Chris from Higgins Haven. Jason’s body is shown to still be lying in the barn as the lake is shown at peace.