Following the events of the previous film, a seriously injured Jason Voorhees goes to a lakefront store for a change of clothes. While there, he kills the store owner Harold with a meat cleaver slammed into his chest, and his wife Edna is impaled in 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 Shelley, his blind date Vera (who does not reciprocate his feelings) and stoners Chuck and Chili. After running into a old man named Abel, who warns them to turn back, the gang meetup with Chris' boyfriend Rick at their destination.
Shelley and Vera get into a confrontation with bikers Ali, Fox and Loco at a convenience store, and are followed back to the haven. When the bikers try to burn the barn down, Jason, who has been hiding in the barn, murders Fox and Loco with a pitchfork before beating Ali with a pipe wrench, seemingly killing him. Later that night, Chris and Rick head out. 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, Shelley wanders into the barn where Jason slashes his throat and takes his hockey mask. The now-masked killer proceeds to shoot Vera in the eye with a spear-gun. Jason then enters the house and slices a head-standing Andy in half with a machete. Debbie has a knife shoved through her chest while resting on a hammock. When the power goes out in the house, Chuck goes down to the basement where Jason hurls him into the fuse box, electrocuting him. Chili 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.
Jason then confronts Chris, who narrowly escapes the house and tries to flee in her van. The van breaks down and Chris makes her way to the barn to hide but is attacked again by Jason, whom she hangs. Jason unmasks himself temporarily to free himself, and Chris recognizes him as 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 take an axe and strike Jason in the head with it, who staggers momentarily towards her before collapsing. Exhausted, Chris pushes a canoe out into the lake and falls asleep.
Chris then has a nightmare of Jason running towards her from exiting the house, and of the decomposing body of Pamela Voorhees - her head reattached - emerging from the lake and pulling her in. The following morning, the police arrive and escort the disturbed Chris from Higgins Haven. Jason's body is shown to still be lying in the barn as the lake is shown at peace once again.