About halfway though The Exorcist, Detective Kinderman visits Chris MacNeil to ask if her friend Burke Dennings (recently found dead at the foot of the stone steps outside her house) may have visited Regan's room the night of his death. They sit at McNeil's dining table and drink coffee. In the room, behind and between them, there's an open doorway, a black rectangle. A void. As they talk, MacNeil realises with dawning horror that her daughter may have thrown Dennings from the window and murdered him—but she conceals this from Kinderman and offers him more coffee. Upstairs, separated from their polite conversation by only beams and plaster, is the girl, the demon, the creature, the murderer.
I've never heard anyone make this observation before—and it's possible my reading is completely wrong—but whenever I watch this scene I think: the black rectangle is Pazuzu. Or at least, it represents MacNeil's forcible severance from the world of normal life and normal people. I certainly don't think the composition's an accident. I wonder if anyone else has thought the same? There's no mention of it in Mark Kermode's book on the film, which surprised me.
