It wouldn't be appropriate to refer to "The Lodge" as a slow-burn horror movie, as this chilly winter-set film is more like a deliberate and punishing freeze. It slowly creeps in, locking the characters into a nightmarish prison from which they cannot escape and leaving them forever altered.

"The Lodge" is the second horror feature from Austrian nephew/aunt filmmaking team of Severin Fiala and Veronika Franz, who broke out in 2014 with "Goodnight Mommy." This time they collaborate with co-writer Sergio Casci on the script, which once again explores the strained relationship between children and their would-be stepmothers, mining terror from the tension.

In the film, Aidan (Jaeden Lieberher) and Mia (Lia McHugh) are reeling from the loss of their mother, Laura (Alicia Silverstone), when their father, Richard (Richard Armitage), tries to orchestrate a bonding family weekend with his new fiancée, Grace (Riley Keough). He deposits the trio at the family's remote cabin in the snowy mountains before being whisked back to town for work. Questionable parenting choices do make the horror movie world go around, after all.

Grace doesn't have the best bedside manner with the kids, though she tries, and her reliance on pills and references to her past as the lone survivor of a suicidal religious cult make her an unreliable heroine. In fact, she's no heroine at all, though in this quietly claustrophobic and deeply unsettling tale, everyone, even the kids, are guilty of something.

While "The Lodge" flirts with the themes and iconography of religious horror, there's no haunting, ghosts or supernatural elements. The confounding occurrences that happen here are deeply strange and disturbing but grounded in reality. What does unfold in the cursed cabin has nothing to do with the lodge itself, but its inhabitants. Fundamentally this is a family tragedy steeped in unrelenting mental illness, trauma and grief, its harsh realism perhaps the scariest thing of all about it.

Fiala and Franz slowly build an oppressive atmosphere and tone with Greek cinematographer Thimios Bakatakis, who has worked extensively with director Yorgos Lanthimos. Bakatakis' camera alternates between pushing in and pulling out on Grace in achingly slow camera movements, creating a sense of the space closing in around her, or revealing a troubling element of the production design (like a painting of the Virgin Mary looming above her head, a reminder of her inescapable traumatic past).

Keough deftly conveys menace and vulnerability in equal parts, and the film hinges around the duality of her performance, which positions Grace as both villain and victim, something Keough is able to convey even in silent stillness. It's unclear who or what is responsible for the strange things that keep happening in the house: All the food, possessions and medications disappear overnight; a beloved pet is lost. Fiala and Franz maintain a resolute objectivity throughout, never letting us into anyone's heads, and the withholding of information is what makes the suspense of "The Lodge" so potent.

Rooted in the world we know, this is a horror film that terrifies because it is all too real and all too human. There's no need for anything otherworldly when human nature can be this horrific, this sad, this tragic. With the remarkably somber and sober "The Lodge," Fiala and Franz follow the consequences of life's brutalities to their logical, devastating ends.