By definition, mothers are the givers of life. As a result, it's especially disturbing when a mother takes the life of a child. An expansion of his own 2009 short film, director Andy Muschietti's feature debut Mama is occasionally short on logic, but sets an effectively spooky atmosphere as it takes the concept of a malevolent mother to terrifying supernatural extremes. A fine companion piece to such Guillermo del Toro-produced nightmares as The Orphanage and Don't be Afraid of the Dark, Mama may not display the nuanced storytelling or iconic imagery of a film written and directed by the man who gave us The Devil's Backbone and Pan's Labyrinth, but it's certainly cut from the same cloth, and serves as a boldly grim debut for ambitious newcomer Muschietti. Victoria and Lilly were just little girls when their father went on a shooting rampage, murdered their mother, and took them to a secluded cabin deep in the woods. In the aftermath of that tragedy, the girls' Uncle Lucas (Nikolaj Coster-Waldau) searched everywhere for his missing nieces. Five years later, Victoria and Lilly are both found living in that very same cabin. Incredibly, they've managed to survive on their own, though years of isolation have left them both in a feral state, and largely unable to communicate. Relieved to find them alive, Lucas and his girlfriend Annabel (Jessica Chastain) welcome the two frightened girls into their home, and work hard to make them feel comfortable. But when a series of ominous events lead Lucas and Annabel to suspect that Victoria and Lilly share ties to an evil beyond human comprehension, the couple must discern whether the two young girls are merely dealing with the emotional aftershocks of a life-altering tragedy, or have attracted a force that could destroy their family all over again. As contemporary horror fans endure a depressing onslaught of sequels and remakes, it's no wonder that fanboys go weak in the knees at the mere mention of the name Guillermo del Toro. A true cinematic visionary, his films frequently deliver breathtaking wonder and deep-rooted terror in equal measure. For that reason alone, it's easy to see why moviegoers hold films that bear his mark to a higher standard than your typical spook show. Despite its intriguingly original storyline, Mama is, in many ways, very much that typical spook show: Character motivations are frequently unclear and shifting; the dialogue is occasionally stilted and laughable; performances -- even from critical darling Chastain -- seem to suffer from the director's lack of experience; and Muschietti's attempts to make his villain sympathetic generally fall flat due to both her reprehensible crimes, and terrifying appearance. Yet for nearly each of the perceived missteps Muschietti and co-screenwriter Barbara Muschietti (the director's sister) make in terms of storytelling, they consistently regain their footing with a series of ghastly -- and occasionally clever -- thrills that have a way of sticking with you. By refusing to offer either an explanation for the gruesome events that set the story into motion, or lay out any clear rules for facing Mama's tenebrous wrath, the Muschiettis succeed in sustaining an effective sense of unease from the first shot to the final shock. Supernatural horror films in particular are notorious for setting up rules that allow the audience an opportunity to gain a certain sense of footing as the story unfolds. By refusing us that, the screenwriters manage to peak our sense of dread early and often. Likewise, their uncompromising approach to the material, as well as the effectively creepy sound design and a willingness to mix jump scares with more fastidious frights, set Mama apart from the pack. Meanwhile, behind the camera, Andy Muschietti and cinematographer Antonio Riestra mount a handsome production featuring horrific visuals directly inspired by such contemporary Japanese horror classics as Ringu and The Grudge. Though the J-horror trend that swept American shores in the early 2000s had arguably run its course by the time Hideo Nakata himself directed The Ring Two in 2005, here, distanced from that dark wave, its tropes seem to take on the air of a long-forgotten nightmare that recurs when we least expect it; we may not be frightened by it as much as we were when it took us by surprise, but that sense of familiarity and impending horror still manage to strike an unsettling chord deep within us regardless. In that respect, much like the way a neglected child still looks up to the flawed parent who gives it their best, many horror fans will still love Mama, regardless of her shortcomings.