Begin your movie with "Once upon a time..." and you might momentarily confuse your audience, luring them into thinking that it's going to be the kind of sanded-down, contempo fairy tale they've come to know: morally correct and drained of real danger. But that's not how fairy tales always were. Not so long ago, before the movies turned each and every one of them into animated features with bouncy-house songs and happy endings, an overwhelming number of those stories were dark, doomy things, full of dread and bad luck befalling the guilty and the innocent.
So, "once upon a time" a man almost shoots his little daughters after murdering their mother. Then Something makes the man disappear, leaving the girls behind in a broken-down cabin in the woods to be raised as feral animals by another -- or maybe the same -- Something. When those children (Megan Charpentier, Isabelle Nelisse) are rescued and sent to live with their caring uncle (Nikolaj Coster-Waldeau) and his punk-rock girlfriend (Jessica Chastain), that Something is not so eager to give up its adoption rights.
Without giving away details, the horror that comes next involves writer-director Andy Muschietti, fellow screenwriters Neil Cross and Barbara Muschietti and executive producer Guillermo del Toro's mostly in-sync vision of ghostliness without gore and more than a little reminiscent of del Toro's earlier child-in-danger-with-monsters story, Pan's Labyrinth. These folks have an intuitive understanding of internalized chaos, the ways that family dysfunction can turn surburban homes into supernaturally haunted traps and, best of all, the pleasures of a really cool, skinny-limbed death-entity living in the closet.
There's stumbling in the dark, missed opportunities to explore the hows and whys of its endangered children's lives and a couple too many blunt physical traumas that stretch the limits of audience disbelief. But the creepshow atmosphere and moments of unexpected humor, an occasional dose of creature-feature goofiness and a third act surprise you really won't see coming effectively smooth over the bumpy bits. Better, still, are the good performances from the terrified/hypnotized kids and especially from Chastain (transcending her on-the-nose Misfits T-shirt) as a non-maternal bass player locked in a hellish version of The Parent Trap. It's a bummer to say it's more than you have any reason to expect from this kind of January-release horror movie, but it's exactly that, a satisfyingly freaky jolt of dark-ride family therapy.