I was thinking about the Ninth Gate a bit the other day, wondering if there was anything comparable that I knew of to the 'Nine Gates', in other words, a rare manuscript that only existed in one or two printings and held secrets able to be found nowhere else (preferably occult secrets). I guess the closets thing I could think of was the Voynich Manuscript (probably not too heavily guarded either, right?)
Then I was thinking of the last scene (spoiler) where Frank Langella is doing the whole ritual thing which he's been obsessing over. He believes so much that it worked that he immolates himself, realizing only when it's too late that it actually hurts and he's about to die. I drew a stark parallel to Christ ont he cross... that is, an obsessed man who has so convinced himself of his godliness that he lets himself be crucified, only at the last second, having a moment of clarity and realizing that he was a madman the whole time and that it's too late to turn back, calling out "my god, my god, why have you forsaken me?' Imagine the terror in both the Langella character, the Christ, and anyone else who only realizes their insanity when the hammer is just about to fall - now that is a horror movie.