“Split” has a hell of a premise. You can just imagine a bunch of Hollywood bigwigs sitting around some marble table, hearing the poor writer pitch it.

“Okay, so there are like these three girls, okay? And one day, they get kidnapped by this creepy man, right? There are taken to some underground cellar, and locked inside. With no hope for escape. But then, they hear the man arguing loudly with a woman. Maybe this is their way out? Maybe there is hope after all? So they yell for help. But when the cellar door opens, the only person in the adjacent room is just the creepy man again. Because, plot twist, get this, their captor has multiple personalities. Twenty-three multiple personalities.”

Mic drop.

It’s an incredibly schlocky premise. One that “Split” doesn’t even try to veer out of. Instead, it embraces its B-movie bona fides, while bringing a remarkable amount of unpretentious craftsmanship to its final product.

The opening I just described could have been awful. Instead, it’s shockingly well-executed and surprisingly underplayed. The director establishes the unique personalities of our three female leads with minimal dialogue – Claire and Marcia are popular girls, while Casey (often shot by herself, alone in frame) is the unpopular loner.

In fact, the film even finds the space to get a laugh out of a silent reaction shot of Casey observing Claire and Marcia being kidnapped, before she, too, is abducted.

Now, my strong praise for “Split” might surprise a lot of people, because, plot twist, get this, “Split” was written and directed by M. Night Shyamalan.

I know what you’re thinking. “M. Night Shyamalan! That guy ruined my favorite childhood TV show/Will Smith/plants. Why the heck would I want to go see a film made by that guy?” And those are all fair accusations. Shyamalan is one of the few directors that can honestly claim to be a household name. But it’s not for any particularly good reason.

And yet there is a bit of a moral arc to Shyamalan’s career. He exploded onto the scene, at the incredibly young age of 29, with the massive critical and commercial success of “The Sixth Sense.” It was the horror film that was so good even your mom liked it, and to this day, it remains by far his largest hit.

After that, he was given immense creative freedom and financial backing. And he initially used it to make “Unbreakable” and “Signs,” two films that were quite successful in their own ways (seriously, I encourage you to re-watch “Unbreakable”).

But things started to go sour around “The Village.” After three films of constant use, the surprise twist ending was starting to feel like a gimmick. Which it always was, but up until “The Village,” it had least been a fun gimmick.

And Shyamalan’s standing only rotted away further when he released the bloated and inconsistent works “Lady in the Water” and “The Happening” back-to-back. Desperate to maintain relevance, he signed on for “The Last Airbender” and “After Earth,” two massive blockbusters which were not even remotely like his typical horror/thriller films. Both failed spectacularly.

But then, an interesting thing happened. After his career hit the lowest point possible (i.e. “After Earth”), Shyamalan decided to get back to his roots. He took a massive pay cut, and made the surprisingly cheap horror thriller “The Visit.” Its biggest star was Kathryn Hahn. The movie was mainly set in one location. Hell, it was a found-footage film. But it was entertaining, which was more than could be said about any Shyamalan film of the previous decade.

And now we arrive at “Split,” which is a remarkably good movie. The direction is solid; pay attention to how effectively and subtly he uses one-takes throughout the film. He’s almost like a neo-Spielberg. The premise is engaging, if completely nuts. And the cast is strong.

But the success of the film also serves to emphasize why Shyamalan was so unsuccessful as a big-budget director. Giving characters pages of dialogue in which they discuss trivial matters that you find interesting comes across as lazy and self-indulgent in a hundred-million-dollar blockbuster. But it can feel rather charming and personal in a small B-movie.

And being deprived of a massive effects budget forces Shyamalan to discover the greatest special effect he’s ever had: James McAvoy.

During the course of the film, McAvoy has to play 23 characters. But more so than that, he has to play 23 characters in such a way that it is obvious that they are all the same person. He can’t rely on elaborate wardrobe changes or makeup. And he acts the hell out of it.

When he’s in the identity of Dennis, the girl’s uptight abductor, he constantly fastidiously fiddles with his shirt buttons. When he’s in the identity of Patricia, Dennis’s co-conspirator to the abduction, he purses his lip and adopts a stern, high-pitched whine. When he’s Hedwig, a precocious nine-year-old that Claire tries to bond with in hopes of escape, he crabwalks out of a room. He’s simply phenomenal.

And for once, there’s no big twist at the end that tries to upend the story or give the film unnecessary weight. So don’t spend the film’s runtime waiting for the other foot to drop. This is just a B-movie. A surprisingly quirky and well-crafted B-movie.

As one addendum, I would like to note that sexual assault does form a significant part of the backstory of one of the main characters.  It’s not advertised, and it’s not shown on screen, but be aware that this content is included.

As for the other part of this film that is generating controversy, the film’s treatment of dissociative identity disorder, I am a little bit more torn on that.

On the one hand, the film’s treatment of the disorder is completely inaccurate. On the other hand, the film is pretty up-front with the fact that it is taking many artistic liberties. Accusing this film of being inaccurate is like accusing “Daredevil” of inaccurately portraying blindness. Or “The Hulk” of inaccurately portraying the long-term effects of radiation poisoning. And if you are using a cheap B-movie to form the entire basis of your understanding of a complex mental disorder, then I can’t help but feel you are kind of an idiot.

Contact Raymond Maspons at raymondm ‘at’ stanford.edu.