Other Mommy: She looks like Mom, she plays with you, and all she asks is that you let her in

In Other Mommy (Rob Savage, 2026), Bela, a seven-year-old girl, lives with her father, Russ, who looks after her at home, and her mother, Ursula, who is absorbed in her job. At night, the girl opens her closet door to invite Other Mommy out to play: a presence with Ursula’s face, also played by Jessica Chastain. The film, produced by Blumhouse and Atomic Monster and distributed by Universal, adapts Incidents Around the House (2024), a novel by Josh Malerman, the author of Bird Box. It opened in the United States and Spain on October 9, 2026. The official Spanish synopsis opens with a single question: may I come into your heart? That is what the entity wants from Bela. And it cannot take it: it has to ask.

// The theoryThe secure base

In 1944, the British psychiatrist John Bowlby published “Forty-Four Juvenile Thieves,” a study of forty-four young thieves from his London clinic. Many of them had suffered long separations from their mothers in their early years. That work gave rise to attachment theory, which Bowlby developed in Attachment and Loss (1969-1980). Its central idea is that children come equipped with a behavioral system that drives them to seek closeness to a caregiver when they are frightened or distressed. If that figure is available and responsive, the child uses it as a secure base from which to explore the world, a phrase coined by his collaborator Mary Ainsworth. From what happens within that bond, the child builds internal working models of who they are and what they can expect from others. In 1978, Ainsworth measured the different attachment styles in the laboratory. Years later, Mary Main and Erik Hesse described the most damaging one: that of the child whose caregiver is at once a refuge and the source of fear.

// The subjectAsking permission to come in

The film tells the story through the girl’s eyes, and the most unsettling detail is the entity’s patience. At first she is a secret: in the trailer, Bela insists that Other Mommy is nice and is not supposed to leave her room. Then she does leave it. One afternoon, while Russ is asleep, a “mother” turns up at the house saying she has come home early from work to have lunch with Bela. Her manner is oddly stilted, and in the end she asks the girl to let her into her heart: it is Other Mommy. When the burning food sets off the smoke alarm, Russ walks into the kitchen and sees her contorted under the counter. Later, at a family party, the entity makes the guests vanish and lifts Bela to the ceiling to force her way into her, without success. And at the home of Frank, a friend of Ursula’s, she plays on the family’s resentments until the girl herself wishes Frank gone. The entity kills him in front of everyone. The paranormal investigators hired by Grandma Ruth give it a name: a trickster demon that wants to take over Bela’s body and life, and cannot do so without her permission. At the end (spoiler), in the basement, Ursula confesses that she never wanted children. Hurt, the girl is on the verge of saying yes. But she remembers what her grandmother taught her and refuses again and again, until she defeats it. Malerman’s novel ends far more darkly.

// The crackThe theory explains the victim, not the monster

Attachment theory is a theory of child development. Here it does not explain why the entity does what it does, because the entity has no psychology: it is a demon that wants a body. What it explains is the door, and why Bela opens it. That reading is more useful, and also more uncomfortable, because it shifts the focus from the aggressor to the victim. The same pattern appears in the criminology of child grooming: in 2006, Samantha Craven and her colleagues defined it as the process by which a person prepares a child, the significant adults around the child and the environment for abuse. The groomer picks a child with an unmet emotional need, offers the attention the child lacks, asks the child to keep a secret and draws the child away from the adults who could offer protection. And the groomer seeks something very like the permission Other Mommy demands: for the child to believe they consented.

The second crack is older. Bowlby was criticized for placing the weight of the bond on the mother. Michael Rutter, in Maternal Deprivation Reassessed (1972), showed that the quality of care and family discord mattered, not just separation from the mother. And as early as 1964, Schaffer and Emerson had observed that babies form attachments to several people, the father included. Some critics have faulted the film for exactly this: treating Ursula’s job as a character flaw. In Bela’s home the main caregiver is Russ, and current theory does not require the secure base to be the mother. The blame for what gets in through the crack belongs to whoever gets in.