Five friends have a lousy time at a cabin in the woods. Miserable time can be blamed on a book (The Evil Dead). The next night something horrible takes over our hero (Evil Dead II: Dead by Dawn) making even more people miserable. In the end everything turns out OK when Ash gets sucked back in time by a giant vortex and is revealed to be the Chosen One.
The geek in me is always annoyed by "fans" who don't seem to know there's a difference between Evil Ash and Bad Ash. Evil ash is the guy Ash turns into after the evil got into his hand. Bad Ash is what happened when one of the mini-Ashes got inside Ash and grew up, eventually getting killed and then coming back from the grave. Evil Ash is possessed Ash, Bad Ash is a magical evil clone. Note Evil Ash's missing hand and the fact Bad Ash has two hands. Yeah I know "Nerd".