If you loved Split, try The Sixth Sense
A bridge between a film you've already seen and one most people haven't. Here's what they share, and what the second one does that the first one doesn't.
What they share
Both films are directed by M. Night Shyamalan, and they both carry the dread, mindfuck mood tags, and they sit in Thriller territory. If that's the register that drew you to Split, the second film will land in a comparable space — through a different lens.
dreadmindfuck
What The Sixth Sense is
Philadelphia, autumn, a child's whisper. A young boy's eyes, a psychologist's worn office, the shadows of people only one of them sees. This film lands best on a quiet evening.

