real Carla Moran extensively for both the novel and screenplay. "She was experiencing something that was both unexplainable and terrifying, she didn't know what to do, where to go or who to turn to."

According to the psychiatric community, her problems stemmed from a troubled subconscious which was erupting into violent self-abuse.

Parapsychologists, however, hoped to establish that she was actually being attacked by something not of this world.

Barbara Hershey, who has never before had so challenging a vehicle to explore the full range of her talents, expressed a mixture of excitement and trepidation about tackling this emotionally explosive and complex role.

"To tell you the truth, I was a little afraid going in," the actress admits. "It's a very physical role and I like that because your intellect doesn't get in the way. But I was more afraid that it might affect me psychologically, going through what I would have to go through to accurately portray this woman's torment.

"The thing that's surprising -- and terrifying -- about this film is that we really did try to approach it realistically. We asked 'what would you really feel like if something this terrifying and incomprehensible actually happened to you?', rather than going for some glamorized special effects fantasy."

The fictionalized Moran (like the real Carla) is a woman who has experienced a good deal of adversity in her life and suddenly finds herself being used not only by this unseen assailant but by the very powers to whom she has turned for help.