A military experiment to create a race of super-warriors go awry, and legions of murderous zombies are unleased upon a surburan neighborhood.

12-year-old Regan MacNeil begins to adapt an explicit new personality as strange events befall the local area of Georgetown. Her mother becomes torn between science and superstition in a desperate bid to save her daughter, and ultimately turns to her last hope: Father Damien Karras, a troubled priest who is struggling with his own faith.

The time is the distant future, where by far the most precious commodity in the galaxy is water. The last surviving water planet was somehow removed to the unreachable centre of the galaxy at the end of the galactic trade wars. The galaxy is ruled by an evil emperor (John Carradine) presiding over a trade oligarchy that controls all mining and sale of ice from asteroids and comets.