Split (2016)

Split (2016): written and directed by M. Night Shyamalan; starring James McAvoy (Kevin Wendell Crumb), Anya Taylor-Joy (Casey Cooke), and Betty Buckley (Dr. Fletcher): AKA, the movie spoiled by its own sequel. Oh, well. To stay spoiler-free, note that Split is something of a return to form for M. Night Shyamalan when it comes to weird suspense involving psychiatrists and psychiatry. 

James McAvoy plays a man with a lot of multiple personalities (or 'Alters'), some of them evil, some of them good, and some of them ambiguous. He kidnaps three teen-aged girls because he's going to do Something Awful to them. So begins a battle of wits between the teens and Multiple McAvoy, primarily between him/her/them and Anya Taylor-Joy's depressed outsider with her own horrible secret in her past.

M. Night Shyamalan does a fairly solid job of not getting too mired down in the sadism that usually accompanies such closet dramas, and McAvoy really is very good as most of his personalities (though he hams it up with a broad Brooklyn accent). Taylor-Joy is excellent in a role somewhat similar to her star-making turn in The Witch -- as an outsider discovering her own power when faced by dire circumstances. Recommended.