Jessica Chastain Faces Her Own Evil Double in Blumhouse Horror Other Mommy

Universal opens Other Mommy in theaters on October 9. The Blumhouse and Atomic Monster horror gives Jessica Chastain a double assignment: she plays a devoted mom and the thing that has started wearing her face.

Rob Savage directs from a screenplay by Nathan Elston, adapting Josh Malerman’s 2024 New York Times bestseller Incidents Around the House. James Wan produces.

The story

Bela is a little girl living with her parents, Ursula and Russ. Then something moves into the house, a presence Bela calls Other Mommy. It looks just like her mother, befriends her and slowly turns on the rest of the family. The trailers lean hard on one line: the double asking Bela to let her “inside your heart.”

A Malerman adaptation

Malerman broke out with Bird Box, the novel behind Netflix’s 2018 hit with Sandra Bullock. Incidents Around the House is a family haunting told from a child’s point of view, and the author signed on as an executive producer of the film.

The cast

Chastain is no stranger to the genre, with Mama, Crimson Peak and It Chapter Two on her résumé. Joining her are:

• Jessica Chastain as Ursula and Other Mommy;
• Jay Duplass as Russ;
• Arabella Olivia Clark as Bela;
• Karen Allen as Grandma Ruth;
• Dichen Lachman and Arian Moayed.

The filmmakers

Savage broke through with Host, the lockdown horror movie set entirely on a Zoom call, before directing the Stephen King adaptation The Boogeyman in 2023. Elston’s credits include the HBO series Succession.

Cameras rolled in Dublin between May 12 and July 9, 2025, with Lowell Meyer as cinematographer and John Cutler editing. The film runs 93 minutes.

Release

Other Mommy was first dated for May 8, 2026, then pushed to October to land in the run-up to Halloween. Reviews have not arrived yet; the final trailer dropped in mid-September.