For the first half it proceeds as this neoplatonic metaphysical horror in the tradition of weird fiction. And, as long as the mystery is unsolved, the horror aspect remains very strong. Some scenes here are among the best in the genre. In addition, most of the philosophical musings are in the first half too, with the second being a more plot-driven elevation of suspense and scale. But by the middle of the movie the mystery is revealed, and it starts dragging a bit. When I first watched it, I loved it, but this time I found myself bored throughout most of the second half of it. This probably says more about me than the movie though. As I grow older, I'm starting to feel my sense of self gradually dissolve. I'm not sure how much less of a "me" I can be. I welcome this process though, as I hope to fade into non-existence. If not physically, at least mentally.