M. Night Shyamalan may have gone back to basics with this psychological horror-thriller, but he is back to his best as a result. 

****

Sometimes people wish they could be somebody different: a scientist, a doctor, a sportsman, a gardener or a plumber.

But what if all of those people are you stuck in one body?

Dissociative identity disorder (DID), is a mental health condition which affects people with multiple personalities.

With it’s complexity, DID comes with a number of legal issues. Court cases have become far more complicated because of it. Can you convict someone of a crime who claims it was someone else?

Whilst it is still a relatively rare disease, it has been portrayed in books, television programmes and movies with a remarkable frequency- M. Night Shyamalan (Signs) examines it in fine detail in Split; which is written, produced and directed by the 46-year-old.

James McAvoy (Filth) produces one of his most stellar performances as Kevin, who has 23 different personalities within his mind, and a 24th beginning to emerge.

The 38-year-old portrays each personality very distinctly. Just through his facial mannerisms and body language you can clearly distinguish each one- a skill most actors find incredibly difficult.

From the artistic Barry, to the gentle-speaking Miss Patricia, to the creepy Dennis, and then nine-year old Hedwig, McAvoy is frighteningly good at shifting in and out of personalities throughout the first two acts.

After kidnapping three teenage girls and keeping them in his underground hideout, Dennis warns them that identity 24 aka “The Beast” is coming.

As the girls try to find a way to escape, Barry goes to see Dr. Karen Fletcher, a psychologist who is helping Kevin through his DID. It’s evident that each personality is struggling to cope with something, but as we see this one man begin to lose control, we begin to realise the bigger picture. It’s clever storytelling from Shyamalan.

There are terrific performances in this movie besides McAvoy. Following her fantastic outing in The Witch, Anya Taylor-Joy once again puts in a strong display as Casey Cooke (one of the three teenagers kidnapped) whose suffered a traumatic past. Betty Buckley (The Happening) also deserves praise as Dr. Fletcher.

However the film does have it’s flaws. This movie is driven by McAvoy. When he isn’t on-screen, the scenes begin to slow down to walking pace. The use of flashbacks also seem to have an uncertain feel about them. It’s like editor Luke Franco Ciarrocchi has just thrown in at different points of the film for the sake of it.

But they are only small issues in what is overall a very good movie. This does feel like a return to Shyamalan’s old ways of filmmaking. The tense score (by West Dylan Thordson) that plays so very subtly in the background, the lighting of all the shots (cinematography by Mike Gioulakis), the way the film starts as a slow burner but increases the intensity as it progresses towards it’s final act. It is edge-of-your-seat stuff!

Then there is, like in most early Shyamalan films, a twist that comes out of nowhere which is particularly pleasing. What works about this movie is that the director has gone back to basics and is doing what he does best. It’s up there with his best work: Unbreakable, Signs and The Village. It’s been a decade of chomping and changing his technique, which came with little success. But without doubt, Shyamalan is most definitely back to his best.

15, 117 mins