For much of its running length, I was considering writing a review for “Split” (2016) that rated it a perfect 10.  (I am an unabashed fan of M. Night Shyamalan, no matter how reviled he is by other Internet commentators.)  I love the way he frames his shots, I love his dialogue, I love his stories, and I love the strange way he can make a slowly paced film nevertheless absorbing.)

And “Split” looked nearly perfect.  James McAvoy handed in a tour-de-force performance as Kevin, a man with dissociative identity disorder (DID).  (Yes, I am aware of the clinical controversies connected with whether the disorder even exists — I was a psychology student many, many years ago.  I think we should suspend whatever disbelief we have for the purposes of enjoying the movie.)  McAvoy plays his role to perfection.  His “Dennis” persona is particularly frightening, and “Barry,” one of the “good personalities” he portrays, is surprisingly endearing and sympathetic.

Playing off McAvoy wonderfully are Betty Buckley as his gentle psychiatrist and Anya Taylor-Joy as one of three teenaged girls kidnapped by his nastier personalities.  The talented Taylor-Joy was also perfect in her role.  (I last saw her 2015’s “The Witch” and she was also in last year’s “Morgan;” I’m gaining the impression that this promising young specializes in cerebral horror-thrillers.)

I would rate “Split” an 8 out of 10.  It suffers a bit, I think, from two missteps toward the end.  One, this taut psychological thriller takes an ill-advised turn into dark fantasy.  I thought it was amazingly good as a thriller grounded only in the real world — it was far less so with the later jarring story elements.  (I do realize why Shyamalan made this creative decision, and you will too, after watching it and then reading up on it.)  But I still think that this would have been a perfect film if the majority of it focused on McAvoy’s personalities either aiding or misleading his psychiatrist, with Taylor-Joy’s fate hanging in the balance.

Two, this film seemed to suffer from the too-many-endings syndrome that people often associate with Peter Jackson’s “The Lord of the Rings” movies.  We seem to have one denouement that works quite well, then a second that should have been re-shot and re-scripted.  And then there’s another plot strand finally addressed … but it is played so subtly that I’m not even sure I got it.  And this isn’t even counting the significance of the movie’s final line, which works as a fantastic framing device.

About that line … if you’re a Shyamalan fan, then you simply must watch the film until it’s very end, as the camera pans through the coffee shop.  You’ll love it.