Other Mommy Chases a Record Horror Book Adaptation Debut

The scariest thing at the box office this weekend might not be a jump scare. Jessica Chastain's Other Mommy arrives in theaters on Friday, October 9, and early tracking puts its domestic opening between $22 million and $29 million, according to Global Box Office projections reported by Fiction Horizon. If the supernatural thriller lands anywhere near the top of that range, Other Mommy would score the biggest domestic debut for a horror book adaptation since It: Chapter Two, and give Chastain's strange new doppelgänger a real shot at becoming this Halloween's signature monster.

That bar is a high one partly because Chastain set it herself. Her 2013 breakout Mama opened to $28.4 million, and her follow-up IT: Chapter 2 debuted to $91 million, per Deadline figures cited by ComingSoon. Against that history, the lower end of Other Mommy's tracking looks almost modest, while the upper end would make it the genre's biggest literary opening in years and a genuine comeback story for original horror. Which version of the story plays out comes down to reception: presales and reviews, not just name recognition, decide whether tracking holds or slips.

The story behind the story is stranger than the premise. ComingSoon recounts how author Josh Malerman's brother once tucked his daughter into bed, only for the child to wish good night to an "Other Mommy" that nobody else could see — the unsettling real-life moment that seeded the novel. Director Rob Savage, who built his reputation on the screen-native chills of Host before pivoting to studio fare with The Boogeyman, told Entertainment Weekly that Chastain performed most of the entity's disturbing physical work herself, per Fiction Horizon. He has also said he hopes the character becomes a new horror icon that fans dress up as next Halloween, a sign of how much confidence the team has in the creature design.

On paper, the film reads like a prestige-horror package. Savage directs from Nathan Elston's screenplay, adapting Malerman's 2024 novel Incidents Around the House, according to production details listed on Wikipedia. Chastain plays a dual role as Ursula, a mother fighting to protect her child, and the sinister entity wearing her exact face, PEOPLE reports via PrimeTimer. Arabella Olivia Clark, cast at age eight, plays the young lead Bela, with Jay Duplass, Dichen Lachman, Arian Moayed, and Karen Allen in support. James Wan produces through Blumhouse–Atomic Monster, Universal Pictures handles distribution, and the R-rated feature runs 93 minutes on a reported $19 million budget.

Why this Halloween window is loaded

Horror is having a banner year at the box office. Fiction Horizon notes that 2026 breakout hits like Obsession and Backrooms have shown how hungry audiences are for scares, and with Halloween approaching, studios are racing to cash in on that momentum. Other Mommy is Universal's biggest genre bet of the season, and its marketing openly ties the release to that run of hits through Blumhouse and producer Wan. The strategy is a familiar one: hand Halloween crowds a fresh boogeyman with a recognizable star attached, then let word of mouth do the heavy lifting through the holiday stretch.

What the weekend will actually decide

Context from last weekend shows why the tracking range is so wide. Amazon MGM's Verity dominated the frame with $32.6 million, more than two and a half times the haul of runner-up Resident Evil, per the Monday box office roundup from Cocktails and Movies — proof that a literary adaptation can win a weekend without franchise machinery behind it. The open question for Other Mommy is whether its mother-monster premise converts Chastain's prestige-horror audience into opening-weekend ticket buyers, or whether the film plays the long game and builds through Halloween week. Malerman, who also wrote Bird Box and serves as an executive producer here, gets another shot at turning one of his novels into a pop-culture moment — and horror's strongest year in recent memory gets its closing act. A strong debut would also cement Chastain's standing as one of the few modern stars whose name alone can open an original horror film, a category where even established franchises have stumbled.