James McAvoy gives the performance of his career in M. Night Shyamalan’s Split, a thriller that turns a single acting showcase into a sustained exercise in dread. The film finds its power in the space between what we see and what we fear we might see next.
Trailer, via Universal Pictures.
How the Trap Springs
Three teenage girls are taken from a shopping mall parking lot by a man who seems to shift personalities with every breath. Kevin Wendell Crumb, as the body is called, holds them in a basement that feels both clinical and ancient. The girls — Casey, Claire, and Marcia — are played with sharp, believable terror by Anya Taylor-Joy, Haley Lu Richardson, and Jessica Sula.
The setup is simple, but the execution is anything but. Shyamalan does not rush. He lets the camera linger on doors, on shadows, on the quiet sounds of a building that seems to breathe. The tension is slow, deliberate, and almost unbearable at times.
McAvoy’s Many Faces
McAvoy plays Kevin, but Kevin is not one man. He is a host for 23 distinct personalities, and the film asks McAvoy to make each one feel real. He does. The polite, obsessive Dennis. The childlike Hedwig. The stern, protective Patricia. The slick, dangerous Barry. Each one has a different posture, a different voice, a different way of moving through the world.
The performance is not a trick. It is a study in control. McAvoy shifts between personalities with a physical precision that makes the audience forget they are watching one actor. His work here is the reason the film works at all.
Dr. Fletcher’s Warning
Betty Buckley plays Dr. Karen Fletcher, the psychiatrist who has studied Kevin for years. Her scenes are mostly conversations, but they carry the film’s central idea. She argues that the mind can change the body, that belief can alter biology. Split uses her theory to build toward something stranger than a simple escape story.
The doctor’s role is small, but she gives the film its intellectual weight. Her faith in her patient — and her refusal to see the full danger — makes her a tragic figure long before the final act.
What Casey Knows
Taylor-Joy’s Casey is the film’s moral center. She is not the loudest girl in the room, but she is the most observant. Her backstory, revealed in careful flashes, explains why she does not panic the way the others do. She has been hurt before, and that history gives her a strange, quiet resilience.
The film trusts her silence. It does not explain her away. It lets her watch, wait, and act when the moment comes. Taylor-Joy plays her with a stillness that makes the final scenes land with real force.
The Beast Arrives
Split does not end where it seems to be heading. The final act introduces a new personality, one that the doctor’s research only hinted at. The creature called the Beast is a leap into full horror, and Shyamalan stages it with a mix of practical effects and patient framing. The result is a climax that feels earned, even when it pushes past the limits of realism.
One scene stands alone. A single shot of McAvoy, fully transformed, walking through a corridor.
Why It Works, and Where It Stumbles
Split succeeds on several fronts, but not every element holds up equally. Here is how the film’s key pieces rank in terms of effectiveness:
- McAvoy’s performance — the clear highlight, a career-best turn that carries every scene.
- Shyamalan’s direction — patient and precise, building dread through framing and silence.
- Taylor-Joy’s Casey — a quiet anchor whose backstory gives the film its emotional weight.
- The doctor’s theory — intriguing but underdeveloped, more premise than payoff.
- The final twist — bold and connective, but it strains credibility for some viewers.
The film’s dialogue can be clunky, and its treatment of mental illness is more sensational than precise. But as a thriller, it is remarkably effective. McAvoy’s performance is the kind that demands attention, and Shyamalan’s direction shows a master still capable of surprise.
