Jessica Chastain’s ‘Other Mommy’ Is Tracking for the Biggest Horror Book Adaptation Opening Since ‘It Chapter Two’

Horror has been one of the box office’s most reliable success stories in 2026, and Universal is hoping to keep the momentum going just in time for Halloween season. The studio originally dated ‘Other Mommy’ for May 8, then moved it to October 9, placing it in the strongest stretch of the year for scary movies.

The film pairs an Oscar winner with some of the genre’s most recognizable names. Jessica Chastain stars, Rob Savage of ‘Host’ and ‘The Boogeyman’ directs, and James Wan produces through the Blumhouse-Atomic Monster banner. The movie is based on Josh Malerman’s 2024 novel ‘Incidents Around the House,’ and Malerman is also the author behind ‘Bird Box.’

Now the numbers are starting to match the buzz. Global Box Office reports that ‘Other Mommy’ is tracking to record the best domestic debut for a horror movie book adaptation since ‘It Chapter Two’ in 2019, and the film is now projected to earn $22M to $29M this weekend, depending on the reception.

Jessica Chastain’s OTHER MOMMY is tracking to record the BEST domestic debut for a horror movie book adaptation since IT: CHAPTER TWO (2019). It’s now project to earn $22M-$29M this coming weekend, depending on the reception. https://t.co/aUx8HrnmYk

— Global Box Office (@GlobalBoxOffice) October 6, 2026

The story follows Bela, an 8-year-old girl played by Arabella Olivia Clark, whose already troubled family faces a sinister presence that comes out of her closet. The entity looks and sounds just like her mother, Ursula, and Bela calls it “Other Mommy.” What starts as a strange bond turns into a threat as the entity begins tormenting the household.

Chastain plays both Ursula and the doppelgänger, which is a major selling point. Jay Duplass, Dichen Lachman, Arian Moayed and Karen Allen round out the cast. The film is rated R for some bloody violence and language and runs a lean 93 minutes, with screenwriter Nathan Elston adapting the novel.

Not every tracker is aligned, which is typical a few days out. Box Office Theory has pointed to a range of $28.5M to $35M, and Boxoffice Pro now says the film is tracking as high as $35M. Boxoffice Pro’s earlier long-range forecast, published weeks ago, was far more cautious at $15M to $25M.

That upward trend suggests audiences are warming to the film. Boxoffice Pro described ‘Other Mommy’ as surging while riding the original horror wave of 2026, and SlashFilm has asked whether it can follow in the footsteps of ‘Obsession’ and ‘Backrooms,’ two recent horror breakouts. SlashFilm’s take is that it will likely land somewhere between those 2 juggernauts and play more like ’28 Years Later,’ which opened to $30M and grossed $151M worldwide.

Other Mommy _ Official Trailer 2026 https://t.co/rRDIwbIQDp

— 14KARAT Info (@Women4k25) August 5, 2026

The projected range compares well with recent October horror releases. Boxoffice Pro points to ‘Black Phone 2’ at $27.3M, ‘Happy Death Day’ at $26M and ‘Smile 2’ at $23M. The top earners remain far out of reach, since ‘Five Nights at Freddy’s’ opened to $80M domestically.

Chastain has a history here, too. Her 2013 horror hit ‘Mama’ opened to $28.1M and topped the box office, and she also appeared in ‘It Chapter Two.’ Savage’s last wide release, ‘The Boogeyman,’ debuted with $12M, so ‘Other Mommy’ is on track to more than double that figure.

Tracking is only a snapshot, and the $22M to $29M range is subject to change depending on reviews and audience word of mouth. Horror films also tend to be front-loaded, so a strong first weekend does not always guarantee a long run. Still, a genuinely unsettling trailer campaign and a good-looking Halloween window give Universal plenty of reasons for optimism.

If the numbers hold, ‘Other Mommy’ could become the latest proof that original horror can still deliver a major opening. We will know soon enough, with the film arriving in theaters on October 9.

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