Jessica Chastain Plays a Mother and Her Terrifying Double in Other Mommy

Other Mommy, a horror film from Blumhouse and Atomic Monster, opens in US theatres on 9 October. Jessica Chastain plays two roles in it: a loving mother and the entity that takes on her face. Universal Pictures is distributing the film.

The film is based on Josh Malerman’s 2024 novel Incidents Around the House, a New York Times bestseller. Rob Savage directs and James Wan produces.

What the film is about

Young Bela lives with her parents, Ursula and Russ, in an ordinary family home. One day a presence appears in the house that the girl calls Other Mommy. It looks exactly like Bela’s mother, grows close to the child and gradually begins to threaten the whole family. In the trailer the double asks the girl to let her “inside your heart”, a line that has become the hook of the marketing campaign.

From the author of Bird Box

Josh Malerman is best known for his debut novel Bird Box, which Netflix turned into a 2018 film starring Sandra Bullock. Incidents Around the House follows a family whose home is invaded by something posing as someone they love. Malerman is one of the executive producers of the adaptation.

Who is in it

The film marks Chastain’s return to horror after Mama in 2013, Crimson Peak and It Chapter Two. The cast includes:

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

Behind the camera

Rob Savage made his name with Host, a pandemic-era horror film told entirely through a Zoom call, and in 2023 directed The Boogeyman, based on a Stephen King short story. The screenplay is by Nathan Elston, who worked on the series Succession.

Filming took place in Dublin from 12 May to 9 July 2025. The cinematographer is Lowell Meyer and the editor is John Cutler. The running time is 93 minutes.

When to watch

The release was originally set for 8 May 2026 before Universal moved it to October, closer to Halloween. There are no reviews yet at the time of publication; the final trailer arrived in mid-September. Cast and stills are on the film’s page in our AMDB database.