’Kay, let’s get this out of the way—you’re going to hear the word “mama” about 12,567 times in the new supernatural horror flick Mama. Here, I’ll fortify you in advance with some plaintive whimperings of “mama,” “mama,” “mama.” A few other expectations you might want to shake hands with: This isn’t the scariest creepy-kid picture you’re ever going to watch, the ghost gets boring to look at after you’ve seen her nearly as many times as those kids mewling the word “mama,” and lowered expectations make the sum of Andy Muschietti’s debut film far better than its parts.

Mama was originally a short film by brother-sister team Andy and Barbara Muschietti. Badass director Guillermo del Toro was sufficiently scared by the scant 2.5-minute Spanish language horror film, and shepherded it through Hollywood, after which it now sits at your local theater, directed by Andy and cowritten by him and his sis. Only now it’s trimmed with pretty white actors and some CG creature effects.

Mama starts with a business type who loses his marbles off a crumbling fiscal cliff. He shoots his estranged wife and kidnaps his two young girls, his personalized license plate, “N1 DAD,” coughing up irony all over the pure, snowy landscape they escape into. Barreling off a cliff into a forest, the stranded trio walks deep into the woods to find a dilapidated cabin (full of nice mid-century mod chic and rats). There is also a ghost. Dispatching with #1 Dad proves easy, and for five years, the girls live in the woods, getting creepier and more feral as their teeth rot out of their faces. Until the day they’re discovered and put under the guardianship of their uncle, Luke (Nikolaj Coster-Waldau), and his girlfriend, Annabel (Jessica Chastain, made over in Dragon Tattoo style). In partnership with a feral-child expert (?!), the boho couple is bequeathed a fancy new house to care for the two dirt-eaters. Little do they know that crazy ghost mama came along for the ride.

It’s a film that works best in the shadows, propped up by creepy performances from the two skittery kids and a ghost whose intentions are stifling. Individual elements of the story are weak—why is everyone so incredulous that a bass player in a band might make an okay mother? Why are ghost mommies always losing their babies? Why does everyone keep going to the haunted cabin?—but when Mama works, it evokes the same atmospheric claustrophobia and tension that made the short so profoundly scary. Your level of enjoyment will fluctuate depending on how easily you can forgive sketchy plot points and too much face time with a CG beastie. Those spider-walking kids are sure horrific, though. They know how to utter the word “mama” in a way that makes your uterus pucker right the hell up. recommended