James Bishop, a young psychiatric student, joins the staff of St. Andew's Hospital, an isolated and unconventional asylum. What he finds there is unbelievable: blood on the floor and frightened patients who speak of a 'Devil' that will harvest their souls.

Asylum head McCort Bruce Payne (Passenger 57) manages to persuade the young student to remain silent until he witnesses a shocking and gory ritual in which a satanic creature robs the very life force from its victims.