The main character gets thrown back in time to the Middle Ages and finds himself in the role of savior to a population of people about to be attacked by the resurrected dead. Much hi-jinks follow.
The movie has become a cult classic, and quotes from it have even found their way into the videogame Duke Nukem 3D.
The movie had a considerably higher budget than any other Evil Dead film. Sam Raimi was able to obtain the money for this film due to his succesful film Darkman. Army of Darkness did not earn a lot of money at the box-office, however, and Raimi has been unable to find funding for a new Evil Dead movie. There have been rumors of a movie staring Bruce Campbell's character in the Evil Dead films starring in a sequal to Freddy Vs. Jason, refferred to as Freddy Vs. Jason Vs. Ash. Both Raimi and Campbell have expressed interest in another Evil Dead film.