Split is, ironically, a slyly connective work from M Night Shyamalan

Yet another director seemingly completing his comeback, “Split” sees M Night Shyamalan building on the momentum of “The Visit” and nearing a return to his best form as he once again explores the boundary between psychological fact and science fiction.

When three young girls are kidnapped, it’s just the beginning of their nightmare. Their kidnapper is Dennis, one of 23 distinct personalities who inhabit the mind of Kevin Wendell Crumb. But Dennis’ plans for the girls go beyond mere kidnapping. They are to be sacrificed, tributes to a soon-to-arrive 24th personality: ‘The Beast’.

Powered by a terrific set of performances from James McAvoy, the film manages to explore the fascinating dramatic potential of dissociative identity disorder without feeling sensational or exploitative. McAvoy finds ways beyond mere costume changes to make each personality a character in their own right, both through vocal versatility and tremendous physicality, aided by a vulnerable but determined turn from Anya Taylor-Joy (“The Witch”) as Casey, one of the kidnapped girls who hides a dark secret of her own. There’s also a great performance from Betty Buckley as Kevin’s psychotherapist Dr Karen Fletcher who manages to be interesting in her own right despite having to shoulder the lion’s share of the exposition to support the story.

Shyamalan successfully creates an increasing air of suspense and tension, even as his ultimate storytelling goals become clearer. “Split” sees him returning to the rich source material of superhero and supervillain tropes, exploring them from a very different angle than we usually see. Beyond the issues of mental health and kidnapping, there’s a potentially troubling subplot concerning the abusive past of one of the kidnapping victims which may make this uncomfortable viewing for some, especially as it’s left somewhat unresolved in a nailbiting finale.

A successful psychological thriller in its own right, the masterstroke of “Split” is what it casually reveals in a deceptively unassuming postscript before the credits roll. Whether it’s a fun throwback or an indication of the director’s next project, it’s definitely the ending that you’ll be talking about as you leave the cinema.