Years will pass and Freddy Krueger has been forgotten by the children of Elm Street, and if he’s forgotten then he can’t return to fulfill his gruesome needs.
Freddy searches the bowels of hell to find someone he can unleash on the world, to spark the fear back in the children of Elm Street, to make them remember the name Freddy, so he can return from hell.
He finds this in Jason, when he approaches him, Jason is in a hell of his own, where it seems he’s obligated to continue killing even in death. Freddy takes the form of Mrs. Voorhees and appears to Jason, Freddy (as the mother) tells Jason that he’s only been sleeping and he needs to wake up and punish the children on Elm Street. He needs to rise up and make them remember what fear tastes like.
After being motivated by Freddy/Mrs. Voorhees, Jason rises up from the ditch where he lays and starts to walk to Elm Street.
I know this is far fetched, because Freddy’s Elm Street is located in Springwood, Ohio and Jason’s Crystal Lake is located in New Jersey, which means Jason was walking a very long time before he arrives on Elm Street.
Once he’s there he does not hesitate and starts to obey his mother / Freddy’s will and kills whatever teenagers he sees. Of course this starts what Freddy wanted - the fear and his name being remembered.
After Jason kills a lot of teenagers, Freddy is able to return, but is unable to stop Jason from killing. This really irritates Freddy, causing him to pull Jason into the dream world and try to kill him.
That doesn’t work, since we learn that Jason can’t die and he can regenerate tissue which we learn in the tenth Friday the 13th chapter, which takes place after the events of Freddy vs. Jason.
So, the surviving teenagers decide that they’re going to help Jason and bring him back to Camp Crystal Lake so he has home field advantage. Lori the female heroine during these events sends herself into the dream world and pulls Freddy out, so he has no power and Jason now has the upper hand.
As the cabin, where the two horror titans now face each other, burns, Freddy and Jason begin their battle to the death.
More murders continue as they battle and in the end Freddy is killed with the glove he sleighed so many people with, as Jason rises from the lake water and with one last effort wins the battle.
Loris also decapitates Freddy and his lifeless body falls into the lake and the two horror icons float to the bottom, assuming that both are dead.
When first light comes we see fog lifting off of Crystal Lake and Jason Voorhees rising from the water with Freddy’s head in hand. And, before we end this chapter we see Freddy wink at us, leaving the ending up for interpretation.
So I don’t know exactly what year the events of Freddy vs. Jason took place, I’m guessing 2002 or 2003, since that’s when the movie was filmed and released.