Before his "Pacific Rim" opens in theaters, Guillermo del Toro wants to introduce you to the mother of all scary movies, "Mama."

Jessica Chastain (as a close-cropped brunette) stars in the new horror film directed by Andy Muschietti, who is making his feature debut. 

After the brutal murder of their mother, two little girls mysteriously disappear into the woods. Years later, they are found and are taken in by their kindly aunt and uncle (Chastain and Nikolaj Coster-Waldau) who try to re-adjust them to normal life after living as feral children for five years. However, something evil followed them home from the dark woods and begins haunting their new family unit. Could it be dear old mom?

Del Toro is "presenting" the film, which seems to fit in with his earlier films "Pan's Labyrinth," "The Devil's Backbone" and "Don't Be Afraid of the Dark."

Over the past 18 months or so, we've seen Chastain in "Tree of Life," "The Help," "The Debt," "Take Shelter" and "Lawless," but "Mama" appears to be her first foray into horror.

Megan Charpentier and Isabelle Nelisse play the two sisters and they look alternately scary and scared. While there are a few mysterious shots of a huge warehouse/archive straight out of "Raiders of the Lost Ark," the film's horror looks mostly confined to the two tykes in a suburban home, giving it a bit of a "Paranormal Activity" vibe (minus the overused found footage gimmick). All in all, it looks genuinely creepy. 

"Mama" opens January 18.

What do you think of the trailer?