Sometimes truly all you need is a great trailer advertising a killer hook. The trailer for Other Mommy materialized in front of The Odyssey over the summer, without much warning or pre-release hype. It showcases a scene where Bela (Arabella Olivia Clark) talks with her mother Ursula (Jessica Chastain) in the kitchen, as Ursula prepares Bela’s lunch. There are a few increasingly glitchy signs that Ursula isn’t herself, which slowly build until Chastain is tearfully asking uncomfortable questions, while an incorrectly prepared pot of pasta burns on the stove. Bela’s father Russ (Jay Duplass) bursts into the smoke-filled kitchen, where Chastain has disappeared… until Russ is startled by the jump-scare sight of a twisted-body monster with Ursula’s face, suddenly lurking beneath the kitchen counter. Running and screaming ensues, cutting back and forth to a black screen where the title is spelled out, one letter at a time.

This instant grabber of a trailer turns out to be a slightly trimmed-down version of a very early scene in Other Mommy, right down to the title card assembled by shock cuts. Plenty of viewers would probably say that the movie peaks accordingly early. That may be true of the movie’s fortunes, too; though the marketing delivered a strong $27 million opening weekend in North America, reviews have been largely poisonous. The film was not screened early for critics, and of those who ventured out to see it and posted their reviews on Rotten Tomatoes, a mere 17 percent gave it a positive notice.

This isn’t one of those crowd-pleasers where critics just aren’t on the same page as audiences, either; opening-night viewers polled by the CinemaScore firm assigned the film an average grade of “D+” which is pretty low even for the horror genre, where movies routinely dip below the “B” rating generally considered the baseline for mild satisfaction. If Other Mommy does hold up at the box office, it will probably be the lingering effects of that trailer, and the lack of a big Halloween-friendly movie to compete with its second weekend.

So what went so wrong with Other Mommy that made it one of the worst horror movies of the year?

Honestly, I’m not sure—not because I can’t pinpoint what went wrong, but because I’m not sure why people are having such a unified reaction against it. Other Mommy isn’t one of the best horror movies of 2026, but it does a number of things quite well.

First and foremost, it rapidly sidesteps the most over-familiar and tedious elements of the haunted-child narrative. It seemed clear from the trailer that this movie would be about young Bela haunted by a demon that could imitate her mother, which of course would make it difficult for Bela to suss out the difference between her real mom and the evil spirit, and even harder to communicate to disbelieving adults what she’s experiencing. Almost every domestic-themed haunted-whatever movie needs at least 30 or 40 minutes, sometimes vastly more, where important characters steadfastly refuse to believe the haunted person’s claims about what they’re seeing and/or hearing, often disguised as a slow-build towards terror.

Other Mommy dispenses with those clichés so quickly that I wanted to give it a standing ovation. The movie joins Bela already familiar with the Other Mommy presence, and understanding that it’s distinct from her mother (though generally friendly toward it). She doesn’t have to spend much time convincing her parents Other Mommy is real; Russ sees it in the aforementioned early kitchen scene, and it’s not too long before Ursula herself lays eyes on her twisted doppelganger. Both parents are duly freaked out.

The Other Mommy, though most often played by a combination of Chastain and visual effects, also doesn’t limit itself to imitating Ursula. We learn it can take on a number of appearances, all with the goal of goading Bela into letting it into her “heart” – her actual body, which it wants to take over. The family goes on the run together, fruitlessly attempting to escape a creature that’s able to bend and distort not just itself, but the reality around its victims, particularly Bela.

Does this make the evil entity trickier to nail down in terms of what it can do and how it can do it? Yes, but shouldn’t that be the case with more horror movies, that they deal with the inexplicable and mysterious, rather than demons that follow clear-cut rules and can be conveniently banished by over-familiar exorcism rituals? The way that director Rob Savage depicts this creature imitating humans is both dreamlike, with shifts in size and scale, and, perhaps more pointedly, reminiscent of generative A.I. in its many melt-y, menacing imperfections.

The latter might well be accidental thematic resonance, or even the result of actual A.I. being employed in the production. But when one character points out that the Other Mommy’s fingers aren’t quite right – a notorious problem area for generative A.I. – it seems pretty clear that someone is at least having a bit of a laugh at the expense of the technology’s uncanny qualities, framing that not-quite-right imitation of humanity as genuine nightmare fuel.

This makes Other Mommy closer kin to Backrooms than many seem to have noticed; if Savage isn’t as interested in those mostly-empty liminal spaces, the movie still fixes its set pieces in some notably off-putting locations, like a sterile bachelor pad where the family crashes (and increases plenty of unspoken tension), or the overcrowded play space where they attempt to find some respite and instead get cacophonous noise, plastic slides that elongate endlessly, and ball pits that spill out into other locations as if through a portal, like something out of Stephen King.

Eventually, Other Mommy ditches the uncanny in favor of overt explanation. Bela is vulnerable because of a buried secret that her parents are complicit in keeping, and Other Mommy becomes a physical manifestation of their by-nature twisted lies (even though the actual lie is, on the balance, relatively wholesome). As others have pointed out, this means a bunch of exposition and tearful catharsis in the movie’s final half-hour, and it’s no accident that the final confrontation is predicated on the family essentially saying, “OK, we give up, let’s just go face Other Mommy and see what happens.” It’s a disappointing finale to what has served, for about an hour, a fast-paced set-piece machine.

Yet before that over-literalization process begins in earnest, Other Mommy has plenty going for it: Chastain’s work as both the conflicted mother and the fun house-mirror distortion of same; sometimes-startling imagery that goes beyond the over-familiar ghosties of other domestic hauntings; a scene where paranormal experts are confronted with an actual demon and must quickly admit that they’re full of shit; Karen Allen as Ursula’s own woo-woo mother.

Young Clark—really more the star of the movie than Chastain or Duplass— anchors her scenes well. If her performance rides a line similar to other kid actors in horror films, where her nominal age of seven seems to fluctuate by the needs of the story, even that is well-incorporated into a movie that’s partially about not being able to discern when your child might be ready to accept a more complicated, difficult truth than what they’ve previously known. It’s also relatively novel to have a horror movie hinge on the gentler, more polite lies we tell each other, rather than ghastly misdeeds.

This means that Other Mommy does risk silliness, and will probably get some “bad” laughs from certain audiences. But I’m not so sure a movie that gives us a writhing, long-necked Jessica Chastain monster is going for pure, unadulterated seriousness. It’s the very woozy unevenness that makes the movie a weirdly pleasurable experience. In other words, Other Mommy has done her job: This is a not-quite-right facsimile of something familiar, and it’s a little unnerving.