Split

For a little while in the late 1990s and early 2000s, M Night Shyamalan brought respectability to schlock. The commercial success of movies like The Sixth Sense and Signs was accompanied by more critical praise than ghost stories or alien-invasion tales might usually garner.

But that's testament to Shyamalan's skills behind the camera. His scripts were solid genre pieces — sometimes inventively nutty, sometimes entertainingly preposterous — but his skilful direction gave them a veneer of quality, even elegance. He went off the rails there for a while, his venture into big-budget fantasy and science fiction not attracting many fans, but it may have been one of the best things to happen to him.

Because with his last movie The Visit and his new one Split, Shyamalan has well and truly embraced his B-movie roots and delivered nasty, edgy, blackly funny thrills and chills crafted with precision and ingenuity.

Split has the kind of high concept hook the writer-director specialises in, and it's made all the sharper by a powerhouse lead performance by James McAvoy, obviously revelling in the opportunities the role affords him while displaying incredible discipline and control.

McAvoy plays Kevin. And Dennis. And Patricia. And Hedwig. And Barry. The latter four are among 23 distinct, separate personalities within Kevin's mind, developed during childhood as defence mechanisms against horrible parental abuse. But there's a 24th personality on the verge of rearing its ugly head. It's known only as The Beast, and somewhat upsettingly it wants "sacred food". So Kevin has kidnapped three young women — Casey (Anya Taylor-Joy), Claire (Haley Lu Richardson) and Marcia (Jessica Sula) — and imprisoned them in a basement bunker until The Beast makes his appearance. But Casey — no stranger to childhood trauma herself — quickly discerns that she can reason with some of Kevin's personalities, manipulate others and even play them against one another. It may be the only way she and her fellow captives can escape in time. 

Like any enjoyably disreputable thriller, Split flirts with tastelessness — if so inclined, one could make the argument that it's trivialising or even exploiting mental illness or taking too much pleasure in the anguish of its characters. But it feels more like Shyamalan knows which buttons to push — and how hard and how frequently to push them — when it comes to getting a response from the audience. And he has two ideal partners in crime in McAvoy and Taylor-Joy, stunning star of the acclaimed horror indie The Witch.

Taylor-Joy is a remarkable talent who consistently finds just the right level at which to pitch her performance. But it's McAvoy who carries Split. It's some truly breathtaking work, dizzyingly shifting between menace, warmth, charming silliness and something truly deep, dark and disturbing.