Other Mommy: the monster that gets in through the bond

The bedroom light goes off, her parents close the door, and Bela, a little girl, gets out of bed. She is not afraid. She opens the closet so that someone with her mother’s face can come out and play, someone who, unlike her mother, always has time. That is how Other Mommy (Rob Savage, 2026) begins, with Jessica Chastain in both roles: Ursula, the mother, and the entity that imitates her. Based on Josh Malerman’s novel Incidents Around the House (2024), it has been in theaters since October 9 and is this week’s Halloween horror pick. Its marketing turns on the question the entity keeps asking the girl: whether it can go inside her heart.

The monster breaks down no doors. It waits to be let in, and it picks the house where that is easiest: parents drifting apart, a mother who is hardly ever there, a girl left alone with her hunger for attention. Reading it through criminology will not help us understand a demon, which has no psychology. It helps us understand the door. And explaining why the door opens is not blaming whoever failed to guard it.

// The theoryThe secure base

In 1944, the British psychiatrist John Bowlby studied forty-four young thieves from his London clinic and found that many had suffered long separations from the people who cared for them. That work gave rise to attachment theory, which he developed in Attachment and Loss (1969). Its central idea is that children are born 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, it becomes a secure base from which to explore the world, the phrase made famous by Mary Ainsworth. In 1978, with the “Strange Situation,” Ainsworth measured how children react when that base leaves and comes back. From what happens within that bond, the child builds a model of who they are and of what to expect from others.

Read Other Mommy’s full case file · Attachment →

// The caseAsking permission to come in

The Other Mommy case file describes a method more than an attack. At first she is a secret kept in Bela’s room: she is nice, she is not supposed to leave, nobody needs to know. Then she does leave. She turns up at the house after Ursula has gone to work, uses a family party to try to force her way into the girl and fails, and at the home of Frank, a friend of Ursula’s, she plays on the family’s resentments until Bela herself wishes him gone. She kills him in front of everyone. The investigators hired by Grandma Ruth give her a name: a trickster demon that can only take the girl if the girl gives her permission.

That permission is what makes the film more than a jump scare. The criminology of child grooming describes the same pattern. In 2006, Samantha Craven, Sarah Brown and Elizabeth Gilchrist defined it as the process by which an offender prepares a child, the adults around the child and the environment itself for abuse. The offender picks a child with an unmet emotional need, supplies the attention the child lacks, asks the child to keep a secret, cuts the child off from anyone who could offer protection and, in the end, tries to make the child believe they said yes. Other Mommy is supernatural; her method is not.

// The same scriptMothers who are not mothers

Fiction has long found horror in the false caregiver, and each version shows a different piece of it. Mother Gothel, in Tangled, steals the girl and builds the bond from scratch: a tower, isolation and an outside world that is always dangerous, coercive control set to music. Isabella, in The Promised Neverland, is the secure base turned into a farm: the children love her because she cares for them, and she cares for them in order to hand them over. Other Mommy goes one step further, and it is a more uncomfortable step. She does not replace the mother by force, nor from the start: she arrives once the real one has already drifted away and takes a place that was empty. It is the same logic that makes M3GAN so effective with a grieving girl.

// The crackThe working mother is not to blame

This is where the film stumbles into the theory’s oldest mistake. Bowlby was criticized for placing the weight of the bond on the mother, and research soon corrected him. In 1964, H. Rudolph Schaffer and Peggy Emerson observed that babies form attachments to several people, the father included. In Maternal Deprivation Reassessed (1972), Michael Rutter showed that the damage comes from poor-quality care and family discord, not from a mother leaving the house. In Bela’s home, the parent who looks after her day to day is her father, Russ. Even so, several reviews, including Alisha Mughal’s in In Review Online, fault the film for presenting Ursula, a mother with a job and with doubts about motherhood (spoiler: she admits she never wanted children), as the cause of the danger. Current theory does not back that up. A household in crisis explains why there is a crack. The blame for what gets in belongs to whoever gets in.