Jacqueline Byers is "Sister Ann" - a troubled young nun whose relationship with her late, clinically diagnosed schizophrenic, mother has left her determined to take holy orders and to help other people with mental health disorders. She has a nursing position at a church hospital where the Catholic church - under the leadership "Fr. Quinn" (Colin Salmon) and psychiatrist "Dr. Peters" (Virginia Madsen) use scientific and ecclesiastic methods to treat their patients. The former leads their exorcism training regime and it to that that the nun is drawn. Her skills are initially tested when she has t...