Split James McAvoy

M Night Shyamalan has, of course, built his filmmaking career on the surprise plot twist. Yet the biggest jolt from his new film, psychological thriller Split, doesn’t involve a whiplash-inducing 180-degree narrative turn.

No, after giving us a string of cinematic duds over the past decade – Lady in the Water, The Happening, The Last Airbender and After Earth; (2015’s modestly successful exception, The Visit, felt something of a fluke) – Shyamalan manages to shock us this time by delivering a movie that actually works.

An enjoyable piece of B-movie silliness, Split supplies mystery, suspense and creepy trepidation, and boasts a tour-de-performance from James McAvoy in the leading role. Or rather roles. For McAvoy’s character, Kevin Crumb, is a man suffering from dissociative identity disorder and possesses 23 distinct personalities. A 24th, the film ominously suggests, will makes its appearance before the end.

The story begins, however, with one of Kevin’s alter-egos, uptight germaphobe Dennis, abducting three teenage girls from a mall car park and holding them captive in his puzzling underground lair. In due course, the young women encounter several of Kevin’s different personalities – including lisping nine-year-old Hedwig, gay fashionista Barry, and prim-and-proper Patricia – and try to play off one against the others in their efforts to escape.

Split Anya Taylor-Joy

“Hokey supernatural element”

As events unfold, the most resilient and resourceful of the captives proves to be watchful misfit Casey (The Witch‘s Anya Taylor-Joy) rather than her outgoing, confident classmates Claire (Haley Lu Richardson) and Marcia (Jessica Sula). Kevin’s psychiatrist, Dr Fletcher (Betty Buckley), makes some appearances, as well, supplying snatches of pseudo science about dissociative identity disorder’s capacity to unlock the potential of the human brain, and thereby cueing up the even more outlandish turn the story will take before the end.

Of course, coming from Shyamalan, this proves to have a hokey supernatural element. That’s something of a let down, yet even if it doesn’t match the claustrophobic tension and white-knuckle scares of last year’s trapped-underground-with-a-psycho thriller, 10 Cloverfield Lane, Split does offer enjoyable chills. And, McAvoy, providing menace, pathos and humour as he rattles back and forth between Kevin’s different personalities, is a blast.

Certificate 15. Runtime 117 mins. Director M Night Shyamalan