Other Mommy Book vs. Movie: How It Changes Incidents Around the House

By Ahaqir Ishaq | October 9, 2026

Spoiler warning: Major spoilers for Incidents Around the House and Other Mommy follow.

A monster borrowing your mother’s face is disturbing enough. Changing what happens to the child it targets can transform the entire meaning of a horror story.

Other Mommy, which opens in U.S. theaters on October 9, 2026, adapts Josh Malerman’s Incidents Around the House. Directed by Rob Savage and written by Nathan Elston, the film stars Jessica Chastain, Jay Duplass and Arabella Olivia Clark. Universal’s release announcement confirms Chastain plays both Bela’s mother and the entity.

The film preserves the young girl at the center of the haunting, but gives the monster’s imitation of her mother greater visual prominence. The most consequential departure comes at the end: post-release coverage describes a substantially less devastating outcome for Bela.

This comparison draws on the publisher’s excerpt, filmmaker interviews and published accounts of the released movie.

What Book Is Other Mommy Based On?

The source is Malerman’s 2024 novel Incidents Around the House. Eight-year-old Bela lives with Mommy and Daddo while an entity she calls Other Mommy repeatedly asks to enter her heart. Its persistence becomes increasingly threatening as her parents’ relationship deteriorates.

Penguin Random House’s excerpt establishes the child’s first-person voice immediately. Bela initially welcomes the visitor emerging from her closet. That friendliness is part of the trap: she has a relationship with the creature before she understands its danger.

For readers discovering the novel through the film, Books of Brilliance also includes it in our most-read horror books roundup.

The Movie Makes Other Mommy’s Borrowed Face Central

Other Mommy can impersonate people in the novel, including Ursula. Consequently, saying the film invents the monster’s ability to resemble Bela’s mother would be misleading.

The adaptation’s change is one of emphasis. Chastain’s dual casting turns the mother’s face into a central part of the film’s identity. The audience must watch familiar expressions for signs that something is wrong.

My reading of this choice is that it moves some of the fear toward recognition. A frightening stranger announces danger. A frightening version of a parent compromises the person a child would normally turn to for help.

That difference also makes the casting more than a visual gimmick. One performer embodies both maternal familiarity and its exploitation.

Bela’s Perspective Survives the Adaptation

Malerman’s opening uses short observations and everyday conversations to keep readers inside Bela’s understanding. Adults can recognize tensions she cannot fully explain.

The film retains that emphasis. In his interview with The AU Review, Savage says the story is told predominantly through Bela’s perspective and that the entity manipulates her understanding.

Interpretation: The challenge changes with the medium. Prose lets readers inhabit a child’s words; a film must communicate that vulnerability through performance, framing and what the audience is allowed to see. Keeping Bela central matters because an adult-led investigation would create a different kind of story.

The Opening Preserves the Bedtime Unease

The adaptation retains an early connection between bedtime and the unseen visitor. Savage told Entertainment Weeklythat the film opens with the parents putting their child to bed before she acknowledges Other Mommy in the darkness.

He also confirmed that the haunting involves a real paranormal entity.

Those details distinguish ambiguity about the creature’s intentions from ambiguity about whether it exists. The film can leave viewers questioning what the monster wants without treating the entire threat as an imaginary friend.

The Kitchen Horror Comes From the Book

The domestic setting is another continuity. Savage says a kitchen sequence in the novel inspired the corresponding scene seen in the movie’s trailer.

The appeal, he explained, was placing a frightening event in an ordinary daytime environment.

Interpretation: This is an effective adaptation idea because it makes the family’s routine unreliable. Breakfast, food preparation and a familiar table should belong to the safe part of a child’s day. Using that space for a confrontation carries the haunting beyond the expected darkness of a bedroom.

Grandma Ruth’s Home Becomes a Striking Screen Setting

Grandma Ruth is part of the novel’s family network. In the released film, the family’s visit to her home receives a conspicuously Gothic setting.

The Indian Express’s post-release review describes a castle above a rocky beach, with a nearby lighthouse and dogs.

Interpretation: That setting gives the search for refuge a different visual character. A relative’s home might promise reassurance, but a remote coastal building can make that reassurance feel fragile before anything supernatural happens.

The Ending Is the Biggest Change

In the novel, Bela eventually permits Other Mommy to enter her heart. The closing scene places her in an immense empty space while the entity rehearses her voice, suggesting it has taken her body and identity.

The movie gives her a different fate. According to FandomWire’s post-release ending account, Bela defeats the entity rather than losing her body. Ursula and Russ also survive.

That account describes the confrontation as involving Bela’s acceptance of painful truths about her parents. It also notes that the surviving family’s reunion does not resolve their unhappiness.

Interpretation: The distinction is substantial. Malerman’s conclusion makes Bela’s need for companionship part of her defeat. The film leaves her a future, though survival does not restore an uncomplicated belief in her family.

A surviving child and a displaced child produce very different emotional endings, even when the supernatural threat begins with the same request.

Does Other Mommy Preserve the Novel’s Horror?

The adaptation retains Bela, the manipulative visitor and the vulnerability of a troubled household. Its emphasis on a recognizable maternal double gives those ideas a direct visual expression.

However, the changed ending alters the final balance between vulnerability and resistance. Readers drawn to the novel’s bleak conclusion should expect a meaningful departure.

For me, the most useful comparison is whether each version makes Bela’s trust feel dangerous. That is the story’s disturbing foundation: a child must evaluate an offer of affection from something that can imitate the people she loves.

Frequently Asked Questions

Is Other Mommy an original movie?

It adapts Josh Malerman’s novel Incidents Around the House.

Does Jessica Chastain play two roles?

Yes. She plays Bela’s mother, Ursula, and Other Mommy in the mother’s form.

Does the movie have the same ending as the book?

No. Published post-release coverage describes Bela surviving without the entity taking her body, a major departure from the novel.

When did Other Mommy release in the United States?

Its U.S. theatrical release date is October 9, 2026.

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