Despite his reputation, M. Night Shyamalan has never lived and died by the twist. His best films, like Unbreakable or even last year's cheerily nasty wicked-grandparents thriller The Visit, work first as accomplished, emotionally engaging suspense. What's most memorable about them isn't the final-act revelations or even the quietly impressive framing and camera work. It's that rare feeling of being unfixed in genre, of being uncertain just what kind of thriller the film will end up being: fairy tale or found-footage horror? Traumatized study of vengeance and survivor's grief or paranoid superhero story?
Outside of its knockout first scene, in which horror insinuates itself into the everyday, Shyamalan's latest, Split, is never so fruitfully uncertain. You always know just what sort of movie you're watching: an Oldboy/10 Cloverfield Lane–style locked-up-underground thriller spliced with a howlingly ludicrous misunderstanding of mental disorders. Split's also cruel and humorless by Shyamalan's standards, with a wearyingly conventional climax and too many scenes of the villain (James McAvoy) ticking between his 23 personalities -- none of them prove especially compelling. While Kevin (McAvoy) growls about his need to feed the impure girls he's imprisoned to some beast, you're left with little to think about besides whether or not a twist is coming.
Split is still a Shyamalan film, though, which means there are inspired moments and joy in the craft. Anya Taylor-Joy's role mostly consists of her taking the horror in, eyes wide, face not committing to any one emotion until her character can figure out how to manipulate whichever Kevin is standing before her. She's silent and pained, a fascinating presence.