I saw the new documentary about the making of Exorcist 2: The Heretic, "Boorman and the Devil," shortly before watching this for the first time, and that's naturally going to affect how I see it. It's a famously "bad" movie, and that film has some ideas about why that I ultimately don't agree with. If you watch this as if it were an in universe background feature for The Exorcist, or a collection of deleted scenes, maybe then it works. But not as a movie in its own right Louise Fletcher and Linda Blair (when she isn't tapdancing) both impress here, and have a lot of chemistry onscreen but what they're given to do is just not that compelling. (aside, I use a therapeutic strobe light device myself that works roughly along the the same lines, to help induce/change brainwave states and I could write a lot about how that's not how it works, but no one really wanted realism in this movie, did they?) The fundamental problem with this movie isn't Burton's alcoholism or the disastrous locust swarm that shut down production for weeks, it's that it can't seem to create a coherent narrative for the characters to exist in. What the hell does Pazuzu want? What do locusts and magic negro tropes have to do with it? I rather think the director, having shot all of this footage outlining different story lines, was loathe to cut any of it but also couldn't form a coherent story with it.