‘Other Mommy’: Five Biggest Changes From the Book, Including a Crazy Death Scene and a Much Darker Ending

SPOILER ALERT: This story contains major spoilers from “Other Mommy,” now playing in theaters. “Other Mommy” is battling less-than-enthusiastic reviews in order to lead the weekend box office, thanks to a viral trailer that scared audiences nationwide. The film, about a sinister demon who befriends a little girl named Bela (Arabella Olivia Clark) and takes the appearance of her mother Ursula (Jessica Chastain), is based on Josh Malerman’s 2024 novel “Incidents Around the House.” The book, of course, goes much more in depth into Bela’s story, but the film takes plenty of other liberties in bringing the tale to the big screen. Popular on Variety Below, Variety has gathered the five biggest differences between the book and the film, from one jaw-dropping scene the movie adds to the much darker ending of the book. The look of the demon In “Other Mommy,” the demon is skilled at mimicking humans during the whole runtime. There are moments where, as Other Mommy, it has specific tells, like face drooping or levitation slightly off the floor. But largely it’s a convincing mimic. There are more signs of something nefarious in the book, as the demon is more avian in appearance, has less steady facial features, carries a putrid smell and an essence that causes some people to cough. A deadly séance One of the key scenes of the film is a séance set up by Grandma Ruth (Karen Allen), which ends with a well-equipped but naive ghost hunting squad conjuring Other Mommy, and getting unceremoniously killed for their troubles. In the book, a séance is set up by fake spiritualists, who quickly admit that they can’t help and are in over their heads. A change of scenery One of the most memorable setpieces in “Other Mommy” takes place at a Chuck E. Cheese-esque restaurant, where Bela follows who she thinks is a new friend. But, of course, it’s the demon, and Bela is pulled into an endless ball pit as her father Russell (Jay Duplass) and Ursula dive in to find her. Bela is then transported to the sea, and then the family sedan, which is now filled up with the ball pit balls — as well as Other Mommy. It’s a more visually dynamic version of a tense, equivalent scene early in the novel, which takes place at a playground and ends with Bela taking a big fall. But what works on the page is made more arresting for the silver screen and creates a trailer-ready moment. A gory added scene The film’s wildest horror moment is when family friend Frank (Arian Moayed) invites Russell, Ursula and Bela to stay at his fancy mansion after Other Mommy disrupts the couple’s anniversary party. Although they are searching for safety, Bela can sense family tension around Frank, as he is a friend of Russell who is not-so-secretly having an affair with Ursula. While Bela is using the bathroom, Other Mommy approaches her and tricks her into agreeing that their family would be better if Frank wasn’t around. This inspires Other Mommy to gruesomely kill Frank in front of Bela, including blowing his head up in an outrageous explosion of blood. In the book, Ursula simply announces that Frank was found dead in a closet, which is a far less traumatic moment for Bela. That ending In the film, Bela refuses to let Other Mommy into her heart, per the demon’s constant request. This eventually defeats Other Mommy, leaving the happy family of three intact — even though there’s subtext that Bela will always have a little discomfort around her mother. In the exceedingly bleak ending to the book, Bela realizes that the demon has killed and styled itself after her Grandma Ruth, who lures Russell and Ursula to their death. Fully alone, Bela agrees to let Other Mommy into her heart, which effectively means that Other Mommy takes over Bela’s body, and Bela is left in the purgatory that the demon had come from. It’s dark! Watch the “Other Mommy” trailer below.