Motion pictures executive produced by Guillermo del Toro are usually an exciting prospect, which makes 2013’s Mama all the more disappointing. Mama was helmed and co-written by first-time feature film director Andrés Muschietti, who expanded upon his own short movie from 2008 to create this atmospheric ghost story. Given the talent of del Toro, and considering his knowledge of the horror genre, it’s hard to say exactly why he attached himself to this derivative picture, which has its strengths but ultimately underwhelms. It’s supported by a terrific premise, yet Mama is exhaustively idiotic, and falls short in terms of gripping storytelling and emotional impact.

After committing a heinous triple murder, Jeffrey (Nikolaj Coster-Waldau) kidnaps his two young daughters Victoria (Megan Charpentier) and Lilly (Isabelle Nélisse), winding up at an abandoned cabin in the woods. Jeffrey is killed, leaving the girls to survive all by themselves. Five years later, uncle Lucas (Coster-Waldau, again) finally finds his nieces after a seemingly hopeless search, but the girls are in a feral and malnourished state, requiring the assistance of psychiatrist Dr. Dreyfuss (Daniel Kash) to rehabilitate them. Lucas is eventually granted custody of Victoria and Lilly, but only on the condition that Dreyfuss can continue to study the children. Lucas’ girlfriend Annabel (Jessica Chastain) is not too thrilled about the situation, preferring to be left alone. And it soon becomes clear that a spirit known as Mama might have followed the girls to their new residence, and is not pleased with the notion of joint custody.

Although Mama sounds promising, it’s ultimately let down by poor screenwriting and storytelling. Internal logic is almost non-existent here. For instance, Annabel has a disdain for motherhood, but she quickly changes her tune once the girls arrive, giving up her rock music aspirations without an understandable motivation. And the way Annabel warms up to Victoria and Lilly never rings true. Added to this, Dreyfuss says he’s a rational man who doesn’t believe in ghost stories at one point, but minutes later he buys the tale of Mama, and begins a terribly clichéd Ring-esque investigation. Oh, and characters have a tendency to explore haunted locations at night-time for whatever reason, and the film culminates with an unsatisfying ending that makes no narrative sense due to the lack of a consistent mythology. Mama admittedly begins with an intriguing prologue that sets the tone, but interest flags as soon as the narrative proper kicks in, with momentum gradually waning. Muschietti’s deliberate pacing grows frustrating, and you will find yourself wanting the film to just get on with it (watching Mama pop up behind unsuspecting characters grows repetitive). There is simply not enough here to sustain the picture’s 100-minute duration, and the subplots designed for padding are treated incompetently (case in point: a subplot involving the girls’ aunt who wants custody of them which leads precisely nowhere).

Relying mostly on jump-scares underscored by loud music cues, Mama is more of a random string of events than a properly considered story. There is no consistent through-line to Mama’s abilities, hence the nature of the paranormal occurrences keeps changing – it’s as if the filmmakers thought about “cool” moments without considering whether or not the non-sequiturs actually serve the plot. For instance, Mama shows up at a hospital once in the movie, taking control of a computer, but never tries such a stunt again. Why doesn’t she shut off the patient’s life support if she has control of the electronic equipment? Making matters worse, the use of digital effects detracts from the experience, as the CGI looks too obvious, making things less scary. Muschietti does a lot of teasing for the first half of the movie, eschewing a full reveal, but we start seeing Mama too frequently and too clearly, which dispels the illusion. Plus, the image of a mess of hair crawling across the floor like a motorised wig looks preposterous. Worst of all is the climax, which reveals Mama to be an unremarkable digitally-created ghoul, taking away all possible intensity.

On a less negative note, Muschietti shows an impressive command of atmosphere, mood and suspense from time to time. Use of shadows is commendable, and it’s unbelievably creepy to see the girls for the first time after their five-year odyssey in the woods. Whenever Muschietti avoids jump-scares, there are some amazingly intense scenes. Furthermore, the acting is better than expected considering the poor scripting. The young girls are especially good, which is borderline miraculous. Equally great is Chastain, who was last seen in the acclaimed Zero Dark Thirty, and who disappears into her role of Annabel here. Also of note is Kash, who could easily be mistaken for Tony Shalhoub.

Mama contains some effectively creepy concepts and nice ideas, not to mention a handful of intense scenes and an occasionally bone-chilling sense of atmosphere, but the end result is too underwhelming, in dire need of a script rewrite. It’s only recommended viewing for avid horror fans who may find something of worth here.