The new Alexandre Aja film “Never Let Go” is billed as a psychological thriller and sports a trailer that looks like a ghost story. Halle Berry stars as a troubled mother surviving what seems to be a postapocalyptic existence deep in the woods with her two young sons. She battles off mysterious creatures, ensuring their safety by remaining tethered to their crumbling wooden cabin with ropes, in a ritual that’s either superstitious or supernatural.

But this isn’t your run-of-the-mill haunting flick. “Never Let Go” reveals itself to be one of the most shockingly bleak American genre films in recent memory, though perhaps that’s not so surprising coming from a French director initially associated with the New French Extremity, who was once named as a part of the “Splat Pack” of up-and-coming horror directors in the early aughts. Aja’s breakthrough feature “High Tension” sported stylized hyper-violence, and he’s known for his gleefully campy creature features like “Crawl” and “Piranha 3D,” but “Never Let Go” is a turn toward more somber storytelling.

As we immediately start to suspect (and as many YouTube commenters have already surmised from the trailer), the “evil” warned of and warded off by Momma (Berry) in “Never Let Go” is all in her head (or is it?). Young Nolan (Percy Daggs IV) starts to question his mother’s methods and rules for their life together: the ropes and their ritualistic blessings, periods of time spent trapped in a small cellar praying on “love” and “evil.”

But Momma’s the only one who can see the zombie-like ghosts of her dead mother and husband, and her sons need to take it on faith that she’s keeping them safe, even as their supplies dwindle. Because it seems so obvious what’s actually going on, all suspense is drained from this story, and it becomes a grim endurance test.

It also doesn’t help that script, by KC Coughlin and Ryan Grassby, is excessively wordy. It opens with Nolan’s voice-over, which harkens to “Beasts of the Southern Wild,” another film about young, semi-feral Black children in the wilderness (although that film embraced magical realism to triumph over challenging circumstances). This narration runs throughout, explaining what Nolan and his brother Samuel (Anthony B. Jenkins) have been taught by their mother about how they exist in relationship to the house, how there’s no outside world left for them.

The style is evocative and creepy, thanks to rich production and costume design, the cramped house seemingly lost in time, surrounded by a damp, mossy forest. Certainly, there is a metaphorical nature to the imagery, and a necessary suspension of disbelief, although everything doesn’t quite tie together in the end. But Daggs turns in a sophisticated performance for such a young actor, and Jenkins is equal parts devastating and menacing.

But “Never Let Go” becomes an unpleasant slog for much of its runtime. It’s never enjoyable to see innocents mistreated or threatened, and there are a series of heartbreakingly miserable sequences that are almost unbearable to watch, without any kind of meaning or payoff to make sense of them.

It’s bold to see an American film be this unapologetically dark with regard to children and animals, and it feels more like a dreary and stark Eastern European film than a spooky season thriller. While that may work for some, for other audiences, it will be a surprise, and not in a good way.

MPA rating: R (for strong violent content and grisly images)

Running time: 1:41

How to watch: In theaters