It looks like a type of disorder that you rarely ever see any more, except in primitive...

Dr. Barringer, Clinic Director: It looks like a type of disorder that you rarely ever see any more, except in primitive cultures. We call it a somnambuliform possession. Quite frankly, we don't know much about it except that it starts with some conflict or guilt that eventually leads to the patient's delusion that his body's been invaded by an alien intelligence, a spirit if you will. Chris MacNeil: Look, I'm telling you again and you'd better believe it: I'm not about to put her in a goddamn asylum! And I don't care what you call it! I'm not putting her away! Dr. Barringer, Clinic Director: I'm sorry. Chris MacNeil: You're sorry! Jesus Christ, 88 doctors and all you can tell me with all of your bullshit is... Dr. Barringer, Clinic Director: There is one outside chance of a cure. I think of it as shock treatment. As I say, there is an outside chance... Chris MacNeil: Will you just name it, for God's sake? What is it? Male Doctor: Do you have any religious beliefs? Chris MacNeil: No. Female Doctor: What about your daughter? Chris MacNeil: No, why? Dr. Barringer, Clinic Director: Have you ever heard of exorcism? It's a stylized ritual in which rabbis or priests try to drive out the so-called invading spirit. It's pretty much discarded these days, except by the Catholics who keep it in the closet as a sort of embarrassment. It has worked, in fact, although not for the reason they think, of course. It was purely the force of suggestion. The victim's belief in possession helped cause it. And just in the same way, this belief in the power of exorcism can make it disappear.