After nosediving with a string of critically panned movies, the career of M. Night Shyamalan seemed for a moment to be a lost cause. However, over the last few years the writer-director has worked hard to re-establish his name, with Split being his latest effort. The psychological horror follows the story of three teenage girls, who are kidnapped by a dangerous man suffering with dissociative identity disorder.

Simply put, Split is a good movie. Although, it might be more accurate to say, Split is a functional movie? The trailer promises an unnerving story built around a man who has clearly lost touch with his sanity, and it delivers on that. However, if this movie were a child, its report card would read ‘could do better’.

Where Split succeeds is in its prolonged tension and stand-out performances. The intensity of the film is sustained for the duration by a number of elements; these include the dreadfully eerie score by West Dylan Thordson, which is particularly effective in the film’s climactic second half. The set design must also be praised, the surroundings of the movie so shabby and forgotten that at times they achieve a nightmarish quality reminiscent of Silent Hill. Shyamalan’s directing also plays a large role, with a frequent use of close-up angles heightening the film’s claustrophobia, while extended shots of James McAvoy’s disturbed Kevin also prove unsettling.

Indeed, it’s difficult not to mention James McAvoy in a discussion of Split. The actor unleashes a previously unseen side to himself in his performance here, portraying a number of personalities with nuanced expertise. Anya Taylor-Joy takes the role of Casey, one of the kidnapped girls which the film revolves heavily around, and does well in the role. She is able to take even the clumsier moments of Split, and express such horror on her face that it’s difficult not to root for her. Betty Buckley is also deserving of a mention, portraying a psychologist who displays a touching level of humanity, although does occasionally veer towards becoming simply an outlet for exposition.

Where Split falls down is in the final third of the movie, where things begin to go off the rails. The film switches genre so abruptly that it gives you cinematic whiplash, and leaves your suspension of disbelief in a state of complete confusion. Effectively traversing numerous genres in one movie is not an impossible feat to master, but here the transition is unfortunately heavy-handed. Not only does it leave the audience disoriented, but the script also feels unable to catch up with the strange developments.

The final third does still manage to entertain on a basic level but ultimately feels like a completely different movie, and this prevents any emotional payoffs from hitting as hard as they could have done. Indeed, numerous moments which should have been catalysts for character growth, end up feeling oddly pointless in the final cut.

But the elephant in the room here is that there is a problem with this movie which is difficult to blame it for. It is as much a fault of audience expectation as it is anything of Shyamalan’s doing. Of course, perhaps the most disappointing thing about Split is that there is no twist ending. There is an epilogue that has certainly got many people talking, but there is no twist linked directly to the plot of the movie.

This being a production from the man who built his career on last-minute surprises, it’s difficult not to spend the film’s runtime taking note of anything that feels like a hint towards an impending shocker. When said shocker never arrives, it makes that clumsy third act just a little harder to swallow. But, as already acknowledged, this is more a lesson in how not to be an audience than it is a genuine critique of this movie.

When all is said and done, Split is a suspenseful psychological horror. Even if it fails to stick the landing, there are thrills to be had here and performances to gawp at. But still, this movie doesn’t quite reach the giddy heights of Shyamalan’s best work, and must instead settle for a passing grade.