A chiller about two abandoned little girls and their bond to the wraith of the title, Mama never delivers the primal terror its premise would suggest. Instead, the movie — the first feature by Andy Muschietti, who coscripted with his sibling Barbara and Neil Cross — distracts with too much foolishness: namely, Jessica Chastain plucking a bass guitar in a jet-black pageboy wig, tattoo sleeve, and Misfits T-shirt.
Mama opens with news of financial panic being broadcast from a car radio and a blond, myopic moppet hearing a gunshot. Her unraveling father scoops up the girl and her toddler sister and drives away so recklessly that their car goes off a cliff. The three stumble upon a cabin in the woods filled with dusty but still fabulous midcentury modern furniture. Dad is about to do further harm to his older daughter but is stopped by a cadaverous, shape-shifting creature.
Cut to five years later: Lucas (Game of Thrones' Nikolaj Coster-Waldau), the brother of that homicidal father, has been searching for his nieces ever since. Once they're found, he and his goth girlfriend, Annabel (Chastain), agree to take in the filthy, feral kids, who have subsisted on nothing but cherries for half a decade. Per the orders of the girls' psychiatrist, Dr. Dreyfuss (Daniel Kash), Lucas, who "draws pictures for a living," and Annabel, whose music has brought in most of the couple's income, must move out of their boho garret and settle with their new charges in a two-story home in Richmond, Virginia, here a bunch of bland suburban streets and a copse played by the province of Quebec.
The older of these savage tykes, Victoria (Megan Charpentier), adapts to this new environment more easily, while Lilly (Isabelle Nélisse) continues to scamper around on all fours and remains essentially preverbal. Yet they retain their tie to vengeful Mama, threatened by these new caretakers. (The possessive specter is performed, with CGI trickery, by seven-foot-tall ectomorph Javier Botet.) Subjecting Victoria to numerous recorded therapy sessions, Dr. Dreyfuss is convinced that Mama is the product of his patient's isolation-induced dissociative personality disorder. But soon this man of science begins to believe in the supernatural, especially when he starts digging around the county records office and a whey-faced clerk tells him: "A ghost is an emotion bent out of shape, destined to repeat itself until it rights the wrong."
Mama's backstory is similar to that of the avenging phantom in last year's superior Edwardian-era-set The Woman in Black. Where the earlier film successfully conveyed deep reserves of grief and despair through lead Daniel Radcliffe's hollow-eyed performance, Mama never registers much beyond a few scares as the beanpole spirit comes racing toward the camera.
In other words, Muschietti's movie, executive-produced by Guillermo del Toro, whose name appears prominently in the opening credits, needs more emotions bent out of shape. Lucas and Annabel display not a trace of apprehension — or disgust — when they become the guardians of these bestial little girls. Any rough patches between the two new parents are soothed by Lucas's assertion, "Hey, I love you, girl." Instead, the unwieldiness is played out in the plot contrivances, confusing machinations involving an aunt who also seeks custody of Victoria and Lilly, convenient comas, stolen computer files, and directives delivered in dreams to go to Clifton Forge and other places with names straight out of the Bobbie Gentry songbook.
A rich mine of (human) parental anxieties left virtually unexplored, Mama does at least feature intriguing, complex performances from its young stars. Victoria and Lilly's growing attachment to Annabel leaves them guilt-ridden about betraying Ghost Mom. (Intentionally or not, the girls' developing relationship with a flesh-and-blood being recalls psychologist Harry Harlow's 1950s studies with infant rhesus monkeys and their different responses to wire and terry-cloth mother surrogates.) But little Lilly, her hair a mess of matted tangles, scarfing down food with dirty hands, never fully abandons her first love, evincing more ambivalence and unruliness than those twice her size. It is she, not Chastain's cardboard punk rocker, who is most deserving of the Misfits jersey.