★★★★☆

Eighteen years after his landmark thriller “The Sixth Sense” premiered, acclaimed director Manoj “M. Night” Shyamalan returns with “Split,” a psychological terror revolving around a man with 24 different personalities.

Shyamalan’s reputation had been recently besmirched by flops like “The Last Airbender” of 2010 and “After Earth” of 2013. Additionally, “Split” has been accused of taking advantage of public prejudice against mental illness for profit. However, “Split” dispels criticism by humanizing the main character through a thorough exploration of the nature behind dissociative identity disorder.

Unlike other thrillers, the success of “Split” does not rely on blockbuster action sequences or jump scares but is rooted in a nuanced exploration into the deepest realms of the human mind.

The movie is focused on Kevin Wendell Crumb (James McAvoy), who has assumed 24 personalities as a result of suffering trauma early in his life. Notable personas include Barry, a flamboyant fashion designer, Hedwig, a 9-year-old boy with a lisp and Miss Patricia, a strict older woman.

McAvoy shines, effortlessly switching accents, mannerisms and demeanors in a complex and haunting performance. Through the incredible work of costume designer Paco Delgado, McAvoy poignantly convinces the audience that they are seeing 24 characters rather than mere facets of a single personality.

Kevin’s varying personalities are revealed slowly as he interacts with three girls he has kidnapped and keeps in his basement. Popular girls Claire (Haley Lu Richardson) and Marcia (Jessica Sula) often make rash decisions that provoke Kevin’s personalities, while misfit Casey Cooke (Anya Taylor-Joy) remains reserved and observant.

Casey’s personality begins to unfold as the movie glimpses into her past, revealing a connection between herself and Kevin. She uses this connection to maneuver around Hedwig, in hopes that Kevin’s inner child might know the secret for getting the girls out. When a final personality, referred to as The Beast, begins to take over Kevin, Casey must rely on her wits, hunting skills and compassion to survive.

The beauty behind “Split” lies in its attempt to make the audience understand and empathize with Kevin and the battles in his mind. Through Betty Buckley’s role as Dr. Karen Fletcher, Kevin’s psychologist and an expert regarding dissociative identity disorder, we begin to understand the origin of Kevin’s personalities, what triggers them and how they can be controlled — if at all.

Fletcher wants the world to see people with the disorder as humans with vast potential, rather than guinea pigs or social outcasts. Kevin is not a reckless monster looking to exact revenge upon the worldbut rather a man who has experienced great suffering and is struggling to regain control of himself.

Whether he intended this or not, Shyamalan crafts a powerful message about mental health and its erroneous perception within society. “Split” reminds us of the dangers and injustices resulting from ostracizing these individuals. Kevin is neither evil nor insane, but he does need support from people like Casey and Dr. Fletcher, who listen and help him make sense of his world.

The movie’s biggest triumph rests in its originality. Kevin is not an archetypal villain, and Casey is not a traditional victim. The film’s plot is intense and unpredictable, presenting constant twists and disturbing sequences. The erratic nature of Kevin’s disorder is enough to create powerful suspense, and, just like Casey, the audience never knows which personality is going to appear next. The film conveys true horror without resorting to gore or violence by simply revealing the extraordinarily sinister potential of the human mind.