Watched The Exorcist at Halloween (as tradition dictates) and formed a theory about the movie’s opening scenes:
The beginning of The Exorcist, when Merrin is in Iraq, is actually the afterlife and the scene is happening after the end of the movie. We see that Merrin is lost in the afterlife and searching for something, this search manifesting as an archaeological dig (why would a priest be at an archaeological dig?)
All throughout this scene there are things foreshadowing what we are yet to see in the movie, but have already occurred for Merrin:
- He finds a rock that is similar to the statues Regan makes.
- They find a St Christopher necklace (and remarks that it is unusual) that is the same as the one Karras loses and that Tom gives to Chris MacNeil at the end.
- Also when Merrin is talking to a man filling in a ledger (God? St Peter?) there is a clock with a swinging pendulum. Later when Karras is dreaming about his recently deceased mother he sees this clock (a sign that he is watching his mother pass over? And maybe her descent into the subway is significant of a darker fate hinted at by Regan later (“Your mother’s in here, Karras. Would you like to leave a message? I’ll see that she gets it.”)
- Merrin goes for a walk and encounters a man with one completely white eye, much like Regan’s eyes which turn white as she floats in the air.
Finally, Merrin encounters a statue which seems to hold some meaning for him. Later in the movie he sees a vision of this statue alongside the possessed Regan. Perhaps this is the first time he sees it and the second time is in the desert, hence his reaction, perhaps he is realising that he has died as he recognises the demonic statue.
Or it’s all explained in the book and it’s just been too long since I read it last.