The Keep is an ambitious visual feast from director Michael Mann, whose previous effort was the moody, stylish Thief, and who would soon produce the quintessential pastel-colored '80s TV series Miami Vice. Adapted from the novel by F. Paul Wilson and set in German-occupied Romania of 1943, the film introduces the invaders to the dark presence lurking within the walls of an ancient fortress in the Carpathian Alps -- a presence which doesn't take well to unwanted guests. When soldiers under the command of Captain Woermann (Jurgen Prochnow) begin to die horribly, he receives the unwanted assistance of Nazi Major Kampffer (Gabriel Byrne), who immediately assumes command and forcibly enlists the aid of the local expert on ancient languages, the Jewish Doctor Theodore Cuza (Ian McKellen), in the translation of the cryptic writings left near a murdered soldier's body. When Cuza comes face-to-face with the Keep's ancient resident -- an ethereal creature which gains strength by draining the life-force from its enemies -- he forms a pact with the creature in the hope that it will escape and destroy Hitler's armies. When a mysterious stranger (Scott Glenn) arrives at the nearby village and befriends Cuza's daughter Eva (Alberta Watson), he reveals the true nature of the beast within the Keep, as well as his intent to destroy it before Cuza can release it -- a task which, if failed, will spell doom for all mankind. The film's fever-dream-logic casts a hypnotic spell -- ably assisted by Tangerine Dream's pulsating, ethereal music (including electronic variations on a theme by Thomas Tallis) -- with a story that seems to play by the Keep's own eerie supernatural rules.
by Cavett Binion synopsis