In M. Night Shyamalan's Knock at the Cabin, the End of Days must be subverted by Andrew (Ben Aldridge), Eric (Jonathan Groff), and their daughter Wen (Kristen Cui) willingly choosing to kill a member of their family, and their reluctance precipitates a series of judgments, each crueler than the last. Four captors prevent them from leaving their cabin while they make their impossible choice, strangers to each other but united by shared visions of doomsday; Leonard (Dave Bautista), Redmond (Rupert Grint), Sabrina (Nikki Amuka-Bird), and Adriane (Abby Quinn).
Each time the terrified trio refuses to select one of their own to sacrifice, one of these "Four Horsemen" is killed by the others, their death unleashing a new phase of the apocalypse. Andrew doubts the legitimacy of the strangers' claims, but after witnessing a series of news reports, Eric, the more spiritual of the two, starts to believe there's a reason he and Andrew were chosen for this unenviable task. As floods, plagues, and death engulf Knock at the Cabin, it becomes more crucial that they make their choice; stop the apocalypse, or wander its ravaged wasteland alone.
Redmond's Death Causes Tsunamis & Earthquakes
Redmond, the most irascible of the four invaders in Knock at the Cabin, is the first person to die after the family doesn't make a decision, and his death spawns massive tsunamis and earthquakes. After Leonard turns on the television, everyone listens to several shocking news reports, watching incredulously as beaches full of visitors are flooded by fifty-foot waves. Washington and Oregon are nearly submerged, and California becomes a tectonic epicenter.
Andrew recognized Redmond after the cabin's invasion began thanks to a violent encounter they shared at a bar years before when Redmond broke a bottle over his head. Andrew tries to use Redmond's criminal past to discredit him in front of the other characters in Knock at the Cabin, but it honestly unsettles him that a man who committed a hate crime against him would allow himself to be killed to reveal the magnitude of the apocalypse. It's a shocking moment that conveys just how high the stakes really are.
Adriane's Death Causes A Plague Attacking Children
Adriane, a young cook, is the second person selected to die after Redmond in Knock at the Cabin, and her death unleashes a plague that specifically begins by attacking children. Once again, Leonard uses the news reports to try to convince Andrew, Eric, and Wen of the gravity of their situation, and the sight of children getting sick and dying in record time seems to have an effect. Though Andrew still wonders if the news reports have been pre-recorded, he can't help but think of Wen as he watches children his daughter's age die.
Before she passes, Adriane tells Andrew and Eric about her son, hoping to appeal to their empathy. It's one of Knock at the Cabin's little twists, but finding out the Four Horsemen's youngest member has a child humanizes her story. Since she prepared them food and was kind to Wen, her death is more emotionally impactful than Redmond's and creates fissures between Andrew and Eric about how to proceed. Anyone who willingly leaves their child parentless would only do so with a good reason.
Sabrina's Death Causes Planes To Crash From The Sky
Sabrina, a kindly nurse, has a less linear death in Knock at the Cabin but nevertheless causes planes to plummet from the sky worldwide. After Andrew is free from his bonds, he makes it to his truck outside where he keeps a firearm in the backseat. When Sabrina chases him down he shoots her, though her final blows are delivered by Leonard, the only one left to carry out their pact.
Of the deaths, hers elicits actual remorse and coincides with Eric seeing a figure in a mirror that makes him think a higher power is involved with everything happening. Sabrina had the opportunity to become close to Eric when she bandaged injuries he sustained during the initial invasion. She partially explained the nature of their ordeal and the decision to find whoever could stop the apocalypse at any cost. Her character in Knock at the Cabin highlights that the Four Horsemen are just regular people, not monsters, who are just as scared as Andrew, Eric, and Wen.
Leonard's Death Causes Darkness & Fires
Leonard, who has acted as the de facto leader of the Four Horsemen in Knock at the Cabin and provided the biggest impediment to the family's escape, is the last to die, bringing about the remaining fire and maelstrom that will engulf the Earth. By the end of Knock at the Cabin, Leonard comes across as a gentle giant who reluctantly carries out his moral mandate. His character's origins are unveiled slowly to create suspense. When it's revealed that he's a second-grade teacher, his righteous empathy makes it clear why he pledged himself to convince this family to end the apocalypse.
With his death, there isn't anything to stop Andrew, Eric, and Wen from leaving the cabin and making their escape, but they will wander the dystopian world alone as its only survivors. At this point, the full brunt of the Four Horsemen's purpose is fulfilled, and the repercussions of their parable truly felt. Leonard knows that while his life is a toll for stopping the apocalypse, the family will pay the ultimate price.
Eric's Sacrifice Saves Humanity & Stops The Apocalypse
Ultimately, Eric decides that he's the one who should be sacrificed to save humanity and stop the apocalypse, much to Andrew's despair. Part of the reason Knock at the Cabin's big sacrifice works is because Eric has come to understand the purpose of the Four Horsemen and has been privy to a particular vision of the future in a way that Andrew can't. The Four Horsemen represent all aspects of humanity, from virtue to malice, that must be comprehended to be cherished. Eric has seen a future full of love and contentment for his husband and daughter that he can preserve.
After Andrew kills Eric with the firearm he intended to help his family escape, he finds Wen in her tree house and breaks the news. Father and daughter eventually take the vehicle the invaders used to find their cabin and head out into a recovering world, unsure about the future but taking comfort in the knowledge that they have one. "Boogie Shoes," the song playing on the radio at the beginning of Knock at the Cabin plays again unexpectedly on the radio, signaling that Eric is with them in spirit and died a hero.