Legend tells of an ancient power residing deep within the Earth, embodied as an ape-like being of unparalleled strength both physically and psychologically. However, the creature split into two distinct parts, one physical and one mental, with the mental aspect permeating the planet and its inhabitants.
Now, evil sorcerers seek to eliminate those possessing the mental piece, leaving weaker minds for the physical aspect to wreak destruction upon the world. When Elaine Beaulieu, a carrier of the mental aspect, falls ill, the ape spirit takes over in a desperate bid to defend itself.
Candid Amantini, sent by the Vatican as an exorcist, uncovers the truth about this omnipotent monster. Japanese girl Nana and amnesiac Nawan Namugyaru unite to stop black magic practitioners from reviving the ancient power and destroying the planet.