The movie starts with Jason being taken to the hospital morgue after being thought dead in the previous movie. However, he soon awakens and escapes the morgue, killing hospital staff and a nurse in the process.
Meanwhile, a group of teenagers and their families arrive at a nearby rented cabin for a weekend getaway. Among them is the child prodigy Tommy, who is obsessed with horror masks and makeup. The group soon becomes the target of Jason's wrath and one by one, they are gruesomely killed.
However, Tommy soon realizes that he may be able to use his skills to fight back against Jason. He creates a mask similar to Jason's and tricks him into thinking he is seeing himself in the mirror, causing confusion and distraction. Meanwhile, the survivors attempt to trap and kill Jason, leading to a final and bloody battle.
In the end, Tommy appears to have killed Jason, but in typical horror movie fashion, the audience is left with uncertainty as Jason's body disappears from the lake.