Getting perturbed that he's giving her the silent treatment, she gives up, grabs a Fangoria magazine and settles into the hammock. As Debbie thumbs through the magazine, blood drops fall onto the pages. She looks up and sees Andy's bloodied body split in two and stuffed above a ceiling beam.
Before she even has a chance to react, Jason's hand pops out from underneath the hammock, grabs her head, and a large knife erupts through her chest from below. We cut to Chris and Rick making their way through the woods, heading back to the cabin. Pausing in their tracks from hearing a noise in the woods, they pick up their pace.
At the same time, Chuck is in the cabin's kitchen making popcorn when Chilli enters and suddenly the lights go out. When Chuck goes to the basement to check the fuse box, he is startled when he sees a dead or stuffed skunk (or weasel) covered with cobwebs. Just as he finds the fuse box, Chuck hears a noise and flashes his light around the room.
We cut back to Chilli in the kitchen, who also hears a noise. She opens the door to find the still alive Shelly, now with a bloody slit throat, but Chilli thinks it another one of his pranks. Shelly stumbles into the cabin, slumps to the floor, and dies.
Back to Chuck, he manages to fix the fuse box and flips on the lever. When he flicks the circuit lever, the lights go on, revealing Jason behind him. Chucks yelps when he turns and sees Jason. The killer grabs Chuck and shoves him into the circuit panel, electrocuting him. In the kitchen, Chilli notices the lights are flickering, not knowing it's caused by Chuck being electrically fried. She turns to Shelly on the floor, angrily kicking him and telling him to knock it off. His body tips over, leaving blood on her hand, she now realizes it's not a prank.
She screams, running into the cabin, calling for the others. She runs upstairs, finds Debbie and Andy's bloodied bodies and screams (off screen). Racing back downstairs, she runs into Jason, who shoves a glowing hot fireplace poker through her stomach, killing her. Jason picks up Chilli's body and walks off. When Chris and Rick return they find the place quiet, empty, the smell of burnt popcorn, and the power out. While she deals with the smoldering popcorn pan, Rick checks the main room, calls out to the others, but no one answers.
He reports back to Chris that they must have taken off without them, which she finds hard to believe. Rick heads outside to find out what's going on. Chris steps out on the porch, calling out to Rick, not knowing that just around the corner of the cabin, Jason has Rick in a grip lock. Holding his hand over Rick's mouth so he can't scream, Chris steps back into the cabin. Jason places his palms on each side of Rick's head, lifting him off his feet, and kills him by crushing his skull. The crunching force causes Rick's eye to pop out.
Chris searches through the cabin, heading upstairs after being hit by water splash. She finds the second floor flooded with water and enters the bathroom. Seeing the bathtub/shower is flowing over with water, she opens the curtain and finds the tub filled with blood stained water and bloodied clothing. She storms out of the cabin, calling for Rick. As she makes her way to the barn, suddenly Loco's upside down body drops down in front of her. Chris screams and bolts for the cabin.
Terrified, she tries to barricade herself in the cabin, but powerful winds are blowing the windows open. Suddenly, Rick's bloodied body comes crashing through the window and the axe-wielding Jason makes his grand entrance. A perilous chase ensues with the two of them exchanging attacks. Trying to keep away from the masked murderer, she slows him down by dumping a bookshelf over him, from upstairs. Chris retreats to a small room and locks the door.
Exploring the room, she pulls back a rack of clothing on hangers and screams when Debbie's bloodied body falls out and topples to the floor. She looks through the keyhole and sees Jason charging the door. He immediately begins chopping away at the door with his axe. Chris looks down at Debbie's body and sees the large knife still embedded in her back. Repulsed at the notion, she nevertheless yanks out the knife.
Jason has splintered a hole large enough to slip his hand in to reach for the lock. Chris immediately lunges forward and drives the knife into his hand. Jason grunts in pain and peddles back as Chris comes charging out, slashing at him with the large knife. He continues backward to avoid the strikes, but she manages to stab him in the leg. Jason crumples to the floor while Chris struggles with a door to escape.
He pulls the knife out of his leg and throws the knife, nearly hitting her as finally gets the door open. In another room, Chris uses a chair to break open a window. Just as she is about to drop down outside, Jason comes in and grabs her jacket, but fortunately her jacket rips, allowing her to fall to the ground. From outside, she peers into the cabin, seeing Jason charging down the stairs. She grabs a fireplace log just outside the door and positons herself for her attack.
Jason steps out, not seeing her while she wallops him over the head with the log. With Jason crumpled over, she makes her break for the van - not knowing the bikers had drained most of its gas. She speeds off, seeing Jason now in the road. Chris floors it to ram him, but he dives away just in time. She doesn't get very far with no gas, and stalls out on the wooden bridge. Jason comes running after her, though he is limping from the stab wound.
Chris flips a switch, apparently the van has double tanks, and she manages to get it started just as the wood is crumbling below the van. However, Jason is now at her side and grabs her throat through the window. She fights him off and pins his hands by rowing up the window and bolts out of the van. Jason smashes the glass with his head to free up his hands, and the chase resumes. Chris races to the barn, secures the door, and hides.
Immediately Jason frees the door and wedges it with a board to keep her from escaping. He begins uprooting potential hiding places, not knowing Chris climbed up on a ceiling rafter. She loses her grip on the rafter just as he looks up to see her come crashing down on him. Chris scrambles for the door but can't get it to open. Jason comes charging at her with the machete, she ducks his strike as the blade buries into the door. Chris scurries up the ladder to the hay loft, blocks the entrance with a hay stack, and grabs a shovel.
Jason easily throws aside the hay stack, entering the loft, and begins searching for her. She has hidden behind stacks of hay with the shovel as her weapon. With his back to her, Chris springs up and whacks him on the head with the shovel, he crumples to the floor. She grabs a pulley and rope, wraps it around his neck, and shoves his body out the loft level opening. Jason falls down and snaps to a stop just before his feet hit the ground. Death by hanging, his body goes limp, or so it appears.
Exhausted, but relieved, Chris makes her way down and finally frees up the door. When she opens the double doors, Jason is there suspended by the makeshift hangman's noose. Suddenly his arms fly up, scaring the crap out of her, pulling himself up to free him from the noose. Jason briefly shows his disfigured face to Chris while trying to get the noose off his neck, which she recognizes him as the man who attacked her two years ago.
As Jason resumes his attack on Chris with his machete, the bikers Ali (who seemingly survived his attack), attempts his revenge on Jason, but Jason severs his right hand and hacks him to his demise. While Jason is hacking up Ali, Chris picks up an axe and slams it down on Jason's skull, causing him to stagger and fall over, seemingly killing him. Chris then wanders over to the lake and falls asleep in a canoe that drifts into the middle of the lake.
The next morning, she wakes up in the canoe. She's so on edge by now that even a drifting log bumping into the canoe and a duck landing nearby in the lake, makes her jump with fright. Suddenly she sees Jason (now unmasked and bloody) appearing in an upper window. He comes blasting through the outer door and charges for the lake. Chris is trying to free the canoe wedged on a log, she looks back . . . no Jason.
Seeing the outer door is still in place, she realizes that it was just her imagination. But suddenly she gets pulled into the water by a decayed, worm-infested Mrs. Voorhees. It is soon revealed that it was just a disturbing nightmare and the police take Chris into the police car. As they drive off the property, she is trashing about in the back seat in complete hysterics. The film ends with Jason's deceased corpse, still with the axe intact in his head and showing the lake in peace once again.