Ironically, I think it’s the film itself that suffers from DID (dissociative identity disorder, or “multiple personalities”). M. Night Shyamalan can’t decide if this is a strict horror film or if it’s more thriller, or character-driven. He jumps right into the plot with minimal fuss: three teenaged girls are abducted by a very methodical man who turned out to be only one personality among many. Captive, the girls try to figure out which of the personalities might be induced to help them, and which ones mean them harm.

The film works as well as it does because James McAvoy was the perfect casting choice (although he was 2nd choice, and only took the role when Joaquin Phoenix had some conflicts). In the hands of anyone else, the disorder might have seemed funny or cartoonish, but McAvoy gives each personality a distinctive flavour without ever resorting to stereotypes. And that’s hard work period, never mind the fact that he’s fighting Shyamalan’s confused script, that seems to want to have something meaningful to say about this controversial disorder, but also really just wants to be an exploitative horror film. You can’t have it both ways.

Split is further testament that M. Night Shymalan has lost his way. He doesn’t know who he is as a film maker anymore, and his lack of confidence is evident in the script and on the screen. Having jumped head first into action, he then seems to regret his choice of not having introduced any of his characters. He bestows back stories on two of them through flashbacks, hoping it’s not too late. The rest remain paper thin. The girls (Anya Taylor-Joy, Haley Lu Richardson, Jessica Sula) are mostly there to scream on cue, and to wear progressively less clothing.

Is it a bad movie? No. No-ish. It’s not without merit. I was drawn in, and stressed out. I had all the right reactions. I just didn’t buy it 100%. You might be tempted, particularly by the film’s end, to say that it’s Shyamalan’s best work since Unbreakable. He’s certainly hoping you’ll say that, banking on it in fact. It’s not the highest compliment, of course, but I’m guessing he’ll take it.