Other Mommy opens in theaters Friday, October 9. Arabella Olivia Clark plays Bela, a young girl who begins speaking to a presence in her home that looks exactly like her mother, while Jessica Chastain plays both the parent and the shape that has learned to imitate her.
Rob Savage directs Nathan Elston's adaptation of Josh Malerman's novel Incidents Around the House. The source story is built around Bela's perspective, an important choice for horror that depends on adults failing to understand what a child can see.
That viewpoint makes the familiar idea of a double feel more intimate. The threat does not simply invade a house. It borrows the face associated with safety, then asks a child to decide which version deserves her trust.
Savage has already shown an interest in horror confined by domestic spaces and limited points of view. Other Mommy gives him a premise where the smallest room in the house can hold the largest uncertainty, and where recognition itself becomes frightening.
