A brainwashed young woman (Elizabeth Olsen) makes the break from the clutches of a sinister rural cult and seeks sanctuary in the bourgeois home of her sister. However, she's still mentally in thrall to the cult's manipulative leader (John Hawkes) and struggles to adjust to life outside its all-pervasive confines. Debut writer/director Sean Durkin has crafted a chillingly dreamlike chronicle of mind control lifted by a sensational breakthrough performance from Olsen as the damaged waif.
The odds must have been on Elizabeth Olsen - younger sister to the vacuous mega-celebrity Olsen twins - following a similarly depthless route onto the pages of Heat magazine and the shallow world of perfume launches.
So the fact that she's turned in a performance of luminous poise and controlled emotion that should have the likes of Keira Knightley, Ellen Page and Mia Wasikowska looking over their alabaster shoulders comes as a bit of a (welcome) shock.
She plays Martha, a gamine beauty who makes the break from a rural "community" - cult to you and me - and calls her estranged sister Lucy (Paulson) from a diner and pleads with her to pick her up.
Uncomfortably settling into a complacently pampered life with Lucy and her architect husband Ted (Dancy) at their idyllic lakeside house, Martha finds she can't shake off the mindset instilled by charismatic cult leader Patrick (Hawkes).
In flashback, we see Martha gently drawn into the psychologically stifling web of the female-centric group and roughly initiated in an early-hours sexual assault by the sinister Patrick.
Gradually her moral compass is knocked out of whack by the parallel universe ruled over by Patrick and his loyal lieutenants, a sort of Amish world in reverse where human evil displaces Christian good.
Even in the des-res sanctuary of her sister's home, the warped ties that bind her to the faraway cult appear unbreakable, fuelling her paranoia as she grows convinced that Patrick and his cohorts will never let her go.
There's a strong seam of Michael Haneke's influence running through this strikingly accomplished debut from Sean Durkin (Brady Corbet - who starred in the Haneke's Funny Games US remake plays one of Patrick's followers).
Olsen is simply stunning as Martha, the mentally frail young woman unable to escape her past, while Hawkes - with more than a hint of emaciated Sean Penn about him - is all too convincing as the sly predator zeroing in for the kill.
This year's Winter's Bone?