There are two reasons to recommend "Mama," a horror film that only looks like the usual fare. One is a pre-fame Jessica Chastain, cast before her Oscar nods for "Zero Dark Thirty" and "The Help," as Annabel, a punk-rock bassist suddenly saddled with two little girls. The other is producer Guillermo Del Toro ("Pan's Labyrinth"), a filmmaker whose brand of the macabre is always invested with emotion. Both make "Mama" more effective than you might expect.
Directed by Andy Muschietti from his 2008 short, "Mama" begins with a nifty premise. Five years after vanishing, sisters Victoria and Lilly (Megan Charpentier and Isabelle Nélisse, both wonderful) are discovered in a cabin in the western Pennsylvania woods, filthy, feral and nearly unable to speak. It's unclear how they survived, but their uncle, Lucas (Nikolaj Coster-Waldau, HBO's "Game of Thrones"), is determined to fight for custody.
He wins, but a freak accident soon lands him in the hospital, leaving prickly Annabel to care for the snarling little raccoons. "I didn't even get the chance to screw them up," Annabel says to a friend. "They came that way."
Despite her tattoos and dyed-black hair, Annabel slowly bonds with Victoria and at least tries to tame the wild Lilly. The relationship among these three turns out to be a genuine heart-tugger, though "Mama" is also a creepy-crawler: Someone, or something, was indeed looking after the girls, and apparently still is.
"Mama" isn't entirely original -- horrormeisters, enough with the moth symbolism! -- but there are plenty of fresh ideas to compensate. Muschietti's camerawork is hugely entertaining (watch for a devilishly clever split screen), and the film's central specter is good 'n' freaky (actor Javier Botet, a 7-foot-tall Spanish beanpole, served as the model). As for the gripping climax, Del Toro's fingerprints, fortunately, are all over it.
PLOT A young couple adopts two mysterious children and, perhaps, a third entity. RATING PG-13 (gruesome imagery)
PLAYING AT Area theaters
BOTTOM LINE A surprisingly effective ghost story, thanks to strong emotional undercurrents and a sharp, smart performance from a pre-fame Chastain.