- "They were warned... They are doomed... And on Friday the 13th, nothing will save them."
In a brief prologue set in 1958, two summer camp counselors at Camp Crystal Lake, named Barry (Willie Adams) and Claudette (Debra S. Hayes), sneak away from a camp fire sing-along to have sex. Before they completely undress, an unseen assailant sneaks into the room and murders them.
The film moves forward to the present: Friday, June 13th. A young woman named Annie (Robbi Morgan) enters a small diner and asks for directions to Camp Crystal Lake, much to the shock of thpatrons and staff. A strange oed Ralph (Walt Gorney) reacts to the news of the camp's reopening by warning Annie that they are "all doomed". Enos (Rex Everhart), a friendly truck driver from the diner, agrees to give Annie a lift halfway to the camp. During the drive, he warns her about the camp and insists she quit immediately, informing her of a boy drowning in 1957, the two murders and serial arson as reasons why the camp is saas superstition and continues her hiking when dropped off at the cemetery. Annie hitches another ride further to the camp with an unseen driver. She starts to panic when the driver speeds past the entrance to the camp and jumps out. The drthe injured girl into the woods, slitting her throat wiAt the camp, Alice (Adrienne King); Bill (Harry Crosby) and Brenda (Laurie Bartram) are busy refurbishing the cabins and facilities with Steve Cristy (Peter Brouwer), their demanding owner. They are joined by the new arrivals, Ned (Mark Nelson); Jack (Kevin Bacon) and Marcie (Jeannine Taylor). With only two weeks left until the camp opens and much work to be done, Steve considers letting his staff quit. As the day goes by, the coplay as various odd things happen. Ned skips out his jobs to play archery, almost hitting Brenda. Alice finds a snake in her cabin, which is killed with a machete. Ned jo relaxation and ruins it by pretending to drown. They get a visit from Ralph, there to warn them of their impending fate; officer Dorf arrives to search for Ralph and warns the group to stay out of trouble while Steve heads back to town to get supplies. All this happens as the killer watches from afar, only identified by a pair of black slacks; brown plaid shirt and a class ring. As a storm starts heading towards the lake, the killer heads into one of the cabins to hide, wearing a black rainslicker. Ned spots the killer, and follows him into the cabin to investigate.
Later that evening as the storm hits, Jack and Marcie go into the cabin to have sex, unaware that Ned's body, his throa. Marcie leaves Jack to use the restroom, leaving him alone with the killer, who has been under the bed the entire time. The killer grabs his head and forces him down while athrough the bed, piercing his throat. The killer heads into the and draws Marcie out of the shower, slamming an axe in
In Alice's cabin, Brenda becomes bored of nothing to do and, wit cannabis, decides Bill and Alice should play "Strip Monoto pass the time. When the door blows open halfway through the game, Brenda realises her cabin window and heads out to shut it before going to be. As Brenda gbed and curls up with a book, a child-like voice calls out . Unsure if it is another prserious call for help, Brenda gives in and heads outside into the rain. The outdoor lighrevealing she has walked into the archeryby the light, she is hit by an arrow and killed.
When Bill returns to Alice's cabin after a quick venture outside, Alice tells him she heard a scream, certain it was Brenda's heard out to Brenda's cabin, where they find a bloody axe (the same one used to killhidden under Brenda's quilt. Searchi to find no one around they start to suspect it isn't a setup to a prank and something serious, though Bill tries to keep Alice calm by suggesting otherwise. The two enter Steve's office and find the phone lines have been cut. They try to take Jack's car out to the town, but it won't start. With a 20 mile walk through the forest and rain out of the question, the two give up and decide to wait at camp for Ste back.
Meanwhile, Steve finishes his meal at the local diner. Remembering they are not as skilled as he is, Steve decides he check up on them. Partway down the road, Steve's car gets stuck in the mud and can't get it out. A passing policeman offers him a ride back to camp, but gets a report of a serious accident
in town and drops him off part way. As Steve walks the rest of the way, he is stopped by a car's headlights at the camp sigwith the driver, he asks what they are doing at the camp. The driver kills him with a knife.
Back at the camp, the power generator unexpectedly dies, forcing Bill to go out and investigate despite not knowing a thing about generators; he insists Alice stay in the cabin rather than follow. When Bill do not return, Alice becomes concerned again and heads out to the cabin to look for him. Opening a closet door, she finds his body pinned to a door by several arrows. Now alone, Alice flees back to the main cabin and hides. After a few moments of silence, Brenda's corpse is hurled through a window.
Alice hears a vehicle outside of the cabin and, thinking it to be Steve, runs out to warn him. Instead she finds a middle-aged woman who introduces herself as Mrs. Voorhees (Betsy Palmer). Mrs. Voorhees introduces herself as the camp's old cook from the 1950s and an "old friend of the Christys". Alice hysterically warns her away, but she insists on going inside to check after being told about the deaths. Mrs. Voorhees expresses horror at the sight of Brenda's body, and starts criticising Steve for trying to open the camp after her son Jason died, having warned him it wasn't safe. Mrs. Voorhees goes on a tangent, describing how Jason had drowned in the lake when the councilors left the lake unsupervised to have sex. After telling Alice that June 13th is her son's birthday, she switches between talking to herself and shouting at Alice, accusing her personally of killing her son. Mrs. Voorhees pulls out a hunting knife, the same one used to kill Annie; wearing a class ring removes all doubt that Mrs. Voorhees is the killer. A lengthy chase ensues, during which Alice flees her attacker and finds Steve's and Annie's bodies, which Mrs Voorhees had carried in her car.
Mrs. Voorhees heads back into the generator room to turn the power back on before continuing the chase. She corners Alice in a storage shed, where Alice finds a shotgun. Before Alice can load it, Mrs. Voorhees attacks her and slaps her around. Alice escapes and runs back to the main cabin, hiding behind a locked door in the pantry. Mrs. Voorhees breaks the door open and rushes in at Alice, brandishing a machete. Alice hits her on the side of the head, knocking her out. Alice sits by the lakeside, hoping that it is all over, but Mrs. Voorhees rushes out of the darkness at her with the machete. Narrowly avoiding the machete, Alice knocks it out of her hands with a paddle and the two wrestle by the lake. Besting her attacker, Alice grabs the machete and decapitates Mrs. Voorhees. In shock, Alice gets in a canoe and rows out to the middle of the lake, where she falls asleep.
Morning comes, and Alice is still asleep in the canoe. Police arrive and call out to her, and she awakens. As she sits up and contemplates her rescue, the decomposing "corpse" of Pamela's son, Jason (Ari Lehman), attacks Alice and pulls her out of the canoe. As she is dragged underwater, she awakes in a hospital. When she asks about Jason, the officer informs that they have never found any boy inside that lake, and then she mutters "then he's still out there".
- Betsy Palmer as Mrs. Voorhees
- Adrienne King as Alice
- Jeannine Taylor as Marcie
- Robbi Morgan as Annie
- Kevin Bacon as Jack
- Harry Crosby as Bill
- Laurie Bartram as Brenda
- Mark Nelson as Ned
- Ron Millkie as Officer Dorf
- Walt Gorney as Crazy Ralph
- Willie Adams as Barry
- Debra S. Hayes as Claudette
- Dorothy Kobs as Trudy
- Sally Anne Golden as Sandy
- Mary Rocco as Operator
- Ken L. Parker as Doctor
- Ari Lehman as Jason
Make-up artist Tom Savini, famous for working with George A. Romero, did the special effects for this movie and Friday the 13th: The Final Chapter.