James McAvoy gives a career-best performance in Split, but the film can’t get out of his shadow. Writer-director M Night Shyamalan can’t match concept with execution, and as a result a hugely entertaining setup is frustratingly squandered with a final half hour that is fatally hampered by grating over-explanation and a chronic mishandling of its central themes.
Split gets right to the point: within minutes of the credits, teenagers Claire (Haley Lu Richardson) and Marcia (Jessica Sula) are kidnapped by an unidentified man (McAvoy). Also among the abductees is sullen, introspective Casey (The Witch‘s Anya Taylor-Joy, continuing to impress), and it’s pretty plainly obvious from the get-go that of our three prisoners, she’ll be the focus – the others scream, panic and make poor decisions, never really pausing long enough to develop as characters in any significant way.
Of course, the real focus here is their captor. The film’s main concept centres around the fact that “Kevin” (McAvoy) has Dissociative Identity Disorder, and is a vessel for as many as 23 personalities, all of whom have names, distinct mannerisms and motivations, and apparently can converse with each other during their downtime. Most of the fun that there is to be had with Split‘s first 90 minutes comes from wondering which persona McAvoy will inhabit when he comes back on screen – whether it’s naive nine-year old Hedwig, the frosty, obsessive-compulsive Patricia or anyone in between, there’s an intensity to his performance that few will equal this year.
While the film generates a fair amount of tension in its scenes in Kevin’s underground bunker, the other ball Shyamalan has to keep in the air is the ongoing work of therapist Karen Fletcher (Betty Buckley). Kevin is among her patients, and her research into the mental and physical differences in his personalities provides Split with most of its narrative momentum, and in turn, its clumsiest expositional info dumps. As the film veers into its maddeningly nonsensical finale, suspense turns to farce and it becomes apparent just how much of Buckley’s dialogue was signed over to Cliffnotes-ing the plot’s complexities. Its approach to its darker themes will satisfy some and offend others, and ultimately, Split suffers from a staggering final-act derailment that obliterates any goodwill it had previously built up, and a landmark performance from McAvoy is left to flounder. A waste.