Before talking about M. Night Shyamalan, something has to be established. “The Sixth Sense” is not that good of a movie. Its twist is one-dimensional and removes any suspense from further viewings, plus Bruce Willis’ hair piece looks awful. For some reason, people give Shyamalan, and subsequently his movies, a pass because “The Sixth Sense” blew their minds way back in the primitive year of 1999. Could any other filmmaker have continued to get work after “The Last Airbender”? I doubt it.

That said, the 46-year-old writer-director seems to be coming back down to Earth after a string of flops and misfires, from “The Lady in the Water” to “Mark Wahlberg Talks to Plants for 90 Minutes” (also known as “The Happening” in some countries). His last picture, “The Visit,” was an effective, if uninspired, take on the found footage genre that made up for its paper thin plot with genuinely frightening action.

His newest endeavor, “Split,” might be his best movie yet. Following their kidnapping, three young girls — led by Anya Taylor-Joy of “The Witch” — must try to outwit and escape Kevin (James McAvoy), a man afflicted by dissociative identity disorder, a mental disorder that has created 23 separate identities within his body. Meanwhile, Kevin’s therapist, played by Betty Buckley is racing to discover and control a possible 24th identity, known simply as “The Beast.”

Even on paper, “Split” clearly has the absurdity of a Shyamalan film. It’s the execution, however, that keeps this movie from devolving into garbage like his other work. For one, the story doesn’t try to become something more than what’s promised in the trailers. Most of the movie’s two-hour runtime focuses on the tense, claustrophobic thriller of the girls trying to escape, with outside action of the therapist and some flashback exposition for Taylor-Joy’s character sprinkled in.

Likewise, the focal point of the movie, Kevin, wouldn’t work without a masterclass performance, and McAvoy knocks it out of the park. I’ve never been particularly struck by his acting before, but in “Split,” he cycles between personalities at the drop of a hat, sometimes even from line-to-line as two different personalities converse with each other. His performance is magnetic, refusing to let you look away as he’s equally hilarious and horrifying.

Despite all of this praise, “Split” is still a movie written by Shyamalan, and there are issues with the narrative. As the movie progresses, it spreads itself too thin, stretching between the therapist’s investigation, Kevin’s actions and the captured girls who are separated from each other at various points. This makes it difficult to fully identify or sympathize with some characters, and their involvement in the story becomes negligible. Additionally, much of the therapist’s dialogue is written to explain the story to the audience, but it lacks subtlety.

Perhaps the film’s greatest error is its exploitative nature. Advocates for understanding DID are already blasting this movie for its gross, unrealistic take on the disease, but there’s also a strange approach taken to childhood sexuality and abuse here. Representation of abuse can be done delicately, but in this case it feels exploitative and insensitive. Once again, the filmmaker is using real issues that people face as tools for his stories, but he isn’t treating them with the respect that they deserve.

“Split” still stands as a new high for Shyamalan, though much of that can be attributed to McAvoy and Taylor-Joy, whose performances complement each other so well. It’s not a revolutionary film by any means, but it fulfills its duty as an edge-of-your-seat thriller with enough Shyamalan in it to surprise you, but not enough to piss you off.

6/10 stars