“There’s something out there.”

In 2008, Bryan Bertino made his directorial debut with one the most effective horror films of the 21st century — The Strangers, a tense, sparse home invasion thriller with an overwhelmingly creepy vibe. Sadly, Bertino hasn’t worked as a director much since then (his only other feature is 2014’s underseen Mockingbird). Equally sad: Bertino’s most-recent return behind the camera, The Monster, fails to live up to the promise of his debut feature.

The Monster follows the usually-successful “horror as metaphor” angle that recent films The Babadook and It Follows adapted so well, but it’s so blunt in its usage that it lacks any real impact. What the film does have going for it, though, is an incredible lead performance from Zoe Kazan. Were it not for Kazan, The Monster would be little more than a cool showcase for some neat practical monster effects. Thanks to Kazan, though, the film is blessed with a layered, and even powerful, performance.

Kazan plays Kathy, a complete mess of a single mother. Battle alcoholism and anger issues, Kathy is taking her daughter Lizzy (Ella Ballentine) to live with Lizzy’s father, Kathy’s ex. The relationship between mother and daughter is strained, to say the least. There’s a bitterness, but also a regret. A wish that things could’ve been different. On the long road trip to drop Lizzy off, Kathy takes a back road, and mother and daughter end up in a horrific car accident. And that’s only the beginning of their problems: there’s something lurking in the woods flanking the road they’re broken-down on. Something with a major appetite.

It’s clear from the get-go that Bertino is using the titular monster to stand-in for the alcoholism and bad parenting plaguing Kathy, and that mom and daughter’s fight to slay the beast represents the futile struggle to best Kathy’s inner demons. There’s no doubt something brilliant, and even poignant, could’ve been done with this set up. Instead, Bertino seems content to just set it up and let it lay there, unexplored. Kazan does all the heavy lifting, bringing a dimensionality to her character that clearly isn’t there in the script. Ballentine, as her frustrated daughter, doesn’t fare as well. The young actress’ performance never once feels natural, which is in stark contrast to Kazan’s realistic portrayal — Ballentine always seems like she’s acting; Kazan seems like she’s truly in peril.

Julie Kirkwood’s darkness-drenched cinematography sets an appropriately unsettling mood, and the score by tomandandy layers under it all nicely, but The Monster never comes across as fully formed. It’s neat to see a practical-effect creature show up and start chomping into people, but it’s not enough to elevate the film above its murky depths. If you’re in search of a great showcase for Zoe Kazan’s considerable acting talent, than The Monster is worth a glance. But those hoping for more Strangers-level greatness from Bryan Bertino will be left out in the cold.