Jessica Chastain’s new horror film Other Mommy hits theatres this Friday — and the title is already sparking debate. Not because of the movie’s plot, but because of a single word: why ‘Mommy’ instead of ‘Mother’? The Oscar-winner has now explained it, and it’s rooted in childhood language, not poetic symmetry. 

The film follows eight-year-old Bela (played by newcomer Lila Karp), who begins to suspect that the woman living in her house, her mother. Isn’t quite real. Jessica Chastain plays both the actual mother and the doppelgänger entity she calls ‘Other Mommy’. The twist? The girl doesn’t refer to her parent as ‘mother’. She says ‘Mommy’. 

In an interview with AP Entertainment, Chastain revealed the origin of the title came from a real-life moment: a man’s brother once walked into his niece’s room to say goodnight. As he turned to leave, the child said, “Goodnight, Other Mommy.” He froze. That phrase, not ‘Other Mother’. Became the seed for the story. 

So the title isn’t about rhyme. It’s about perspective. The entire film unfolds through Bela’s eyes, where emotional intimacy trumps formal grammar. And that matters. 

Chastain called the choice ‘really, really important’, not just for authenticity, but for the psychological unease at the heart of the film. The closer the entity mimics the familiar, the more terrifying it becomes. 

Other Mommy arrives October 9. No car chases. No Bollywood-style stunts. Just a little girl’s voice, saying goodbye to someone who shouldn’t be there. 

And then silence.