You need to watch the most chilling post-apocalyptic thriller on Netflix ASAP

There’s nothing like the apocalypse to fracture one’s family portrait.

The end of the world is often explored more seismically on screen, in movies that shatter tectonic plates or science-fiction that gives society a totalitarian face-lift. But what most terrifies audiences about societal collapse has more to do with the spiritual toll it takes on both the individual and the family unit than the physical devastation it wreaks around them.

Consider The Road, Cormac McCarthy’s masterful prose poem of existential collapse, in which one man shows his son how to carry humanity’s fire forward into unending darkness. Alfonso Cuarón’s Children of Men, which turns 10 this year, draws its power from the apocalyptic notion of mass infertility: no family, no future. That same anxiety drives The Quiet Place movies; even blockbusters like Mad Max: Fury Road frame their surrogate families as the best hope for a species otherwise withering in the desert.

As civilization crumbles into dust, it’s every family for itself. The strain this inflicts on ties that bind is inevitably a focus of post-apocalyptic genre cinema, which often suggests those left alive in the end times will be more of a threat to each other than any one solitary cataclysm.

Trey Edwards Shults’ chilly psychological chamber piece It Comes at Night — streaming on Netflix through December 8 — tells us little of the catastrophe that befell civilization years before its main action. We gradually learn about a highly contagious disease that’s ravaged the planet, but Shults dispenses with expository table-setting to instead introduce his apocalypse in horrifically personal terms.

As the film opens, an older man stricken with the disease says goodbye to his family, his eyes clouded with delirium and his body riddled with sores. What Sarah (Carmen Ejogo) says to the man is muffled by the gas mask she wears and choked with emotion, but her eyes are full of love. Paul (Joel Edgerton) carts his catatonic father outside in a wheelbarrow to the grave he’s already prepared before shooting him in the head and setting his body ablaze. Throughout this despairing prologue, the man’s last gasps overlap with Paul and Sarah’s labored breathing beneath the masks, conveying the sense of a grim world polluted with their grief and fear.

Spared the sight of his grandfather’s brutal euthanasia, Travis (Kelvin Harrison Jr.) waits inside as his parents bury him in a shallow grave. It Comes at Night spends most of its time inside, too, slowly creeping along the expansive corridors of the boarded-up cabin house this family has made a sanctuary. With its boarded-up windows and two locked doors, one painted a malevolent red, the house more resembles a prison, and its geography feels vague and fluid throughout the film, literalizing the characters’ opaque headspaces.

It soon becomes clear that, though the compound’s walls keep the outside world at bay, they do little to dispel the atmosphere of pain, anguish, and grief that has settled into its occupants. Travis was clearly close with his grandfather and has only the family dog to talk to. Paul, an angry and authoritarian figure, takes the role of patriarch so seriously that he no longer serves as a father or husband, instead isolating himself in a state of perpetual paranoia. Sarah, caught between them both, is very afraid.

Further grounding It Comes at Night in unfixed psychological dread is its blurring of nightmare and reality. Travis is tormented by terrible dreams, which swirl ominously and bleed into his surroundings. In the midst of one of these surreal moments, the family’s sanctuary is intruded upon by Will (Christopher Abbott), who claims his family is 50 miles away and in desperate need of water.

Sarah convinces Paul not to shoot this new arrival dead on the spot, as he’s prepared to do to protect what’s his. “My family’s all that matters to me,” Will says, appealing to Paul’s role as a father. “I know you can understand that.” Trying to determine whether Will is lying, Paul travels with him away from the cabin. In one tense sequence, they’re ambushed by a pair of strangers, and we suddenly understand that any of those who survived the apocalypse, including our characters, did so through ruthless self-interest.

After the pair reach Will’s wife, Kim (Riley Keough), and young son, Andrew (Griffin Robert Faulkner), Paul stays with them for long enough to see they’re not infected, leading them back to the cabin at gunpoint. Once Paul and Sarah lay out their rules — including that the only entrance to the house stays locked — the families let down their guards and grow close.

For Travis, the arrival of this second family — and especially the soft, sweet-natured Kim — stirs long-repressed fascinations. Ever-vigilant, Paul sees and certainly doesn’t care for the way his son withdraws from him and toward the less harsh and unyielding Will.

One night, the fragile trust brokered between these two families begins to splinter as Travis finds Andrew sleeping inexplicably in the wrong room, the front door slightly ajar, and his beloved dog bleeding and clearly sickened. Did the child unlock the door while sleep-walking? Did he go outside? Has he been infected?

Once this paranoia takes hold, it’s suffocating — and unstoppable. It Comes at Night begins as Travis’ ordeal — complete with visions of his deceased grandfather dribbling black bile. But it gradually becomes Paul’s personal hell, as he quarantines his family away from Will’s and begins preparations to confront the members of the household he believes to be infected. From there, the film proceeds with pitiless logic and reaches hopeless conclusions, though its abstracted, shadow-soaked atmosphere is even more effective in conveying the despair of characters living out their worst nightmares.

Before making It Comes at Night, Shults directed the acclaimed, semi-autobiographical Krisha, another agonized family saga, which charted the fallout of a lifelong addict’s return to the fold for Thanksgiving. Shults acted in that feature too, casting his real aunt Krisha Fairchild in the title role and infusing the narrative with a soul-shattering honesty that deepened its horrors. Beyond probing open wounds, Shults’ movies are exorcisms, so meticulous in their anguish and punishing in their sense of inevitability that they serve as pure embodiments of his dread.

The post-apocalyptic setting of It Comes at Night makes for an appropriately atmospheric container in which Shults can isolate, confine, and study what scares him: the specter of loss, the certainty of remorse, the impossibility of closure, the futility of believing we can protect the ones they love. These are recognizable, implacable emotions; they offer It Comes at Night its relentless tension and bone-chilling force.

It Comes at Night is streaming on Netflix through December 8.