Everything We Know About Other Mommy - 2026

Other Mommy (2026) is shaping up to be one of the most intriguing supernatural horror releases of the year. Directed by Rob Savage, produced by James Wan through Atomic Monster alongside Blumhouse, and starring Jessica Chastain, the film adapts Josh Malerman’s 2024 novel Incidents Around the House, written by the author of Bird Box.

The story follows Bela, an eight-year-old girl whose troubled family life becomes even more frightening when a mysterious presence begins appearing inside her home. Bela calls the entity “Other Mommy,” and what makes it especially disturbing is that it can take the appearance of her real mother. Instead of behaving like a conventional monster, the entity tries to earn Bela’s trust and repeatedly asks one chilling question: “Can I go inside your heart?” That concept gives Other Mommy its strongest hook. The danger is not simply something hiding in the darkness, but something that looks familiar, sounds loving, and knows how to exploit a child’s vulnerability. For fans searching for Other Mommy 2026, Jessica Chastain horror movie, or Incidents Around the House movie, that disturbing premise is likely to be the film’s biggest attraction.

Jessica Chastain is another major reason expectations are high. She plays both Bela’s mother and the supernatural entity that imitates her, creating a dual performance built around subtle differences in expression and behavior. Chastain has said she wanted Other Mommy to appear warm and welcoming while still feeling fundamentally wrong, using a fixed smile and an unblinking stare to create discomfort. Rob Savage also seems well suited to the material. After Host and The Boogeyman, he has experience turning familiar domestic spaces into places of fear.

The film is told largely from Bela’s perspective, which could make the story more unsettling. A child may not immediately recognize manipulation, and the entity appears to use that innocence against her. Rather than attacking only through violence, it becomes emotionally intrusive, presenting itself as someone who understands Bela while tensions between her parents continue to grow.

The source material adds another layer of interest. Incidents Around the House uses a child-centered perspective to create uncertainty, because audiences experience frightening events through Bela’s limited understanding. Translating that idea to film is one of the adaptation’s biggest challenges, but it could separate Other Mommy from conventional haunted-house stories.

The supporting cast includes Arabella Olivia Clark as Bela, Jay Duplass as her father, plus Dichen Lachman, Arian Moayed, and Karen Allen. Nathan Elston wrote the screenplay, while James Wan’s involvement brings another major horror name to the project. Promotional footage has emphasized family tension, unsettling appearances of the entity, and the sense that the threat is spreading beyond Bela’s bedroom. The trailers suggest psychological horror, supernatural dread, disturbing imagery, and violent moments rather than nonstop gore. That combination may appeal to viewers who enjoy films such as The Babadook, The Boogeyman, and The Conjuring, where atmosphere and emotional fear matter as much as the supernatural threat.

Other Mommy is scheduled to open in U.S. theaters on October 9, 2026, with an October 8 release planned in Argentina under the title Madre siniestra. The movie was originally expected earlier in the year before being moved into the Halloween season. Its announced runtime is 93 minutes, and it has received an R rating in the United States for bloody violence and language. No confirmed streaming date has been announced. The main question is whether the film can turn its strong premise into sustained fear.

The ingredients are there: Jessica Chastain in a dual role, Rob Savage directing, James Wan producing, a popular modern horror novel as the source, and a monster whose greatest weapon may be trust rather than brute force. Among upcoming horror movies 2026, Other Mommy stands out as a notable October genre release. If the adaptation preserves the novel’s disturbing child perspective and emotional manipulation, Other Mommy could become a talked-about Halloween supernatural horror film.