Father Lankester Merrin (Stellan Skarsgard) is conducting an archeological dig in East-Africa when he discovers remnants of a pagan church. After abandoning the priesthood due to his experiences in World War II, Father Lankester Merrin must rediscover his faith to combat a foe that's cunning, unrelenting, and immortal.
Having abandoned his faith in God, Father Merrin (Stellan Skarsgard) joins a British archaeological excavation in Kenya, where an inexplicably pristine Christian Byzantine church has been unearthed – looking as if it had been buried on the day it was completed. But beneath the church, something much older sleeps, waiting to be awoken. As madness swiftly descends upon the villagers and the British soldiers, Merrin watches helplessly as the atrocities are committed against a helpless village – atrocities he had seen before and prayed never to see again. The blood of innocents flows freely on the East African plain, and the horror has only just begun. In the place where evil was born, Merrin will finally see its true face.
An adventurous photojournalist, Ted (Michael Pare), has always responded to the call of the wild, traveling to the ends of the Earth to capture his images. On one expedition in Nepal, he encounters a horrific, half-human beast that murders his girlfriend and bites him, leaving him scarred forever. When Ted returns to the tranquil Pacific Northwest, his sister Janet (Mariel Hemingway) notices a disturbing change in her brother: he has a furtive way of avoiding her questions and a strange glint in his eye. By night, Ted secretly transfigures into a werewolf. The secret, however, may be out as the protective family dog, Thor, has his suspicions.
Mia Baran (Isabelle Adjani) and Nicole Horner (Sharon Stone) develop a devious plot to murder Mia's overbearing husband Guy Baran (Chazz Palminteri). After drowning Guy, Mia and Nicole dispose of the body in a murky pool, hoping that anyone who finds his body will come to the conclusion that he drowned. When the pool is drained, no body is found, leaving the women to wonder if Guy actually died. Will the women get away with bloody murder? Or has someone removed the body of the victim to play mind games with them?
Police Lieutenant Kinderman (George C. Scott) begins to notice eerie similarities between the murder investigation he's currently working on and the techniques utilized by the infamous "Gemini Killer" (Brad Dourif) who was executed fifteen years prior. A hospitalized mental patient comes forward claiming to be the "Gemini Killer" but he resembles a priest Kinderman knew who passed away during an exorcism. As more casualties amount, Kinderman begins to investigate the connections between the two allegedly deceased.