The horrible past of Camp Crystal Lake is all but forgotten. As the towns people attempt to forget the police force insure that no one enters the wretched Camp "Blood" (Crystal Lake). After the bloody disappearance of Alice, the young camp councilor that killed Mrs. Voorhees and survived, five years pass and all is quite. Everything seems to be looking up........that is until Paul Holt decides to open a camp councilor training center at a camp across the lake from none other than Camp Crystal Lake. A mysterious figure begins to stalk the shadows of the young campers from the start and watches their every move. On the first day Mr. Holt and his assistant Ginny Field take the group to the lake so they can swim, or tan, or just have some fun in the sun before the work begins. When two young councilors (Sandra Dier and her boyfriend Jeff) decide to wonder off and check out the old camp. Upon arriving in the camp they find bloody remains of some sort of animal and just as they are about to leave the local sheriff's deputy (Deputy Winslow) appears and takes them back to the camp where they belong. Deputy Winslow informs Mr. Holt that he must keep all of the kids off of Camp Blood grounds, that it has been five quite years and they want to keep it that way. The deputy continues by saying that if he catches anymore of the kids over there he would arrest them. Nodding that he agrees as the deputy is walking out Mr. Holt says he will take care of it all.
While on his way back into town the deputy see's someone run across the road and head for Camp Crystal Lake. He immediately assumes that more of the kids from Mr. Holts group have decided to look into the old camp. Jumping from his car and giving chase he ends up outside a makeshift and rundown trailer. As he walks through the trailer he hears something outside and goes to check it out, but before he makes it out the door someone murders him with a blunt force to the head. While back at the center Mr. Holt informs the campers that the day was the last fun day tomorrow the work begins. He also tells them that he will take anyone who wants one last night on the town into town with the exception of their two explorers (Sandra and Jeff) who have volunteered to stay back and watch the camp along with a few others who actually volunteer. As the night drags on and most of the camp leaves for a night on the town the few who remained back attempt to find something fun to do......but someone is watching them all from the shadows.
One girl decides to go for a swim and after getting scared goes to get her clothes only to discover they have been taken. It is quickly revealed that another of the young men from the camp took them and she chases him where he is suddenly swept up into a tree thanks to a little trap. As the girl grabs her clothes and runs back to camp to get a knife to cut him down the mysterious figure appears and cuts the boys throat. Upon her return the girl believes the boy is only playing around then realizes that he is actually dead, the figure then kills her as well. Slowly the figure makes its way to camp and kills off the others who chose to stay back.
Soon after Mr. Holt and his assistant Ginny return to find the camp appearing to vacant. As they search they suddenly find that they are not alone when a man wearing a potato sack over his head leaps from the shadows and attempts to kill Mr. Holt. After a short fight the figure stands and after a horror filled scream Ginny runs with the man in fast pursuit. The somewhat lengthy chase ends inside a cabin on the grounds of Camp Crystal Lake where Ginny discovers the decapitated head of who can only assume was Mrs. Voorhees. Afraid and disgusted Ginny slides on Mrs. Voorhees's old sweater in an attempt to fool Jason. When Jason bust through the door she immediately begins talking to him as if she was his mother, while also hiding the machete behind her back. At first it works Jason believes that she is his undead mother, until she moves to swing the machete and he see's his real mothers head. Quickly Jason throws up his pitch fork blocking Ginny's attack when suddenly Paul appears in the door way and tackles Jason. After the two wrestle for a short bit Ginny slams the machete through Jason's shoulder. Ginny and Paul then retreat back to their cabin on the other side of the lake where they stumble upon Muffin ( a dog that belonged to one of the campers). As Ginny calls Muffin into the cabin an unmasked Jason leaps through the window and begins to pull her out. When Ginny awakes she is being put into an ambulance and is told that she was the only survivor, she has no recollection of what happened to Paul.