You certainly can’t fault Alistair Legrand’s The Diabolical for a lack of ambition. Instead of trying to be one genre picture it attempts to be three: a haunted house thriller, a sci-fi mystery, and finally a slasher. Or, to be more precise, it begins as The Babadook (2014), becomes Primer (2004), and ends as Friday the 13th (1980). I’ve always believed that a filmmaker should risk failing spectacularly instead of settling for safe, boring mediocrity. And honestly The Diabolical feels more like a miscalculation than a cash-in. So I’ll give Mr. Legrand the benefit of the doubt. But that doesn’t save the fact that his film doesn’t work.
The film focuses on Madison (Ali Larter), a single mother of two contending with a violent son named Jacob (Max Rose), a possibly insane daughter who talks to “spirits” named Haley (Chloe Perrin), a shady businessman from an even shadier research company trying to “buy” their house, and a gaggle of other-dimensional monsters who periodically crawl out of dryers and through walls, go “booga-booga-booga,” and disappear. Uneven plotting result in a difficult-to-follow first act, jolting the audience from disjointed scenes which seemingly have nothing to do with each other: a duo of paranormal investigators flee from Madison’s house in terror, Haley chastises one of the ghosts, and Jacob gets a hands-on physics lesson from one of his schoolteachers about how to properly throw an egg against a wall without breaking it. Later on, said schoolteacher reveals that he once worked as a scientist developing teleportation technology at the aforementioned shady research company. And of course, his name is “Nikolai.” I guess “Edison” would have been too on the nose.
As the film funnels all its disparate plot threads into the second act, its in-universe logic begins to break down before collapsing with a pitiful gasp of an ending. For a while Madison treats her children’s periodic possessions and transformations into tattooed hell-babies as a psychosomatic malady and refuses to let them leave the house—despite experiencing the exact same hauntings and having the ensuing property damage usually accompanying hosting murderous demon-beasts as proof that the supernatural goings-on aren’t just figments of their imaginations. This all seems like a cheap excuse for explaining why Madison doesn’t just take her family and move out, essentially solving all of their problems.
Without going too deeply into spoilers, we learn that the monsters are actually failed time travel experiments from the future and the main monster…actually, I’m not sure who the monster is supposed to be. What matters is that it goes on a kill-crazy rampage in the house in the third act before even more time-travel shenanigans ruin any hope of figuring out what in the hell is going on. Clearly The Diabolical needed another screenplay draft, perhaps another dozen.