How Shyamalan’s Knock at the Cabin rewrote the book’s ending for a big twist

M. Night Shyamalan’s new movie is based on the book A Cabin at the End of the World, and largely follows it — until it doesn’t.

This article contains spoilers for Knock at the Cabin.

There are two inevitable questions that accompany every M. Night Shyamalan movie: Is there a twist? And okay, what is it? His newest film, the apocalypse horror movie Knock at the Cabin, is no exception.

There is a twist, but it’s not a traditional Shyamalan one; don’t think of Bruce Willis being dead in The Sixth Sense, or the village being an expansive LARP exercise in The Village, or the beach that makes you old actually being a beach that makes you old in Old.

The wrinkle is that Shyamalan’s movie, which he co-wrote the screenplay for, is actually based on the 2018 bestseller A Cabin at the End of the World, written by Paul Tremblay. While the premise remains the same — two gay dads and their child are terrorized by four radical home invaders who claim an apocalypse is coming — Shyamalan’s movie takes a completely different turn, and changes not only the ending but also the themes, message, and moral questions posited in Tremblay’s novel. The result is a film that will appeal to fans of the emotional torture depicted in A Little Life, with a very clear answer on whether this gay family saves the world.

The big change in Knock at the Cabin

Knock at the Cabin, for the most part, sticks to the “rules” of the novel. The family — Andrew (Ben Aldridge), Eric (Jonathan Groff), and Wen (Kristen Cui) — are told that they must sacrifice and kill one of their own in order to stop the apocalypse from happening. That kill cannot be accidental or suicidal and must be a decision made with a clear mind. If they choose not to kill one of their own, one of the visitors — Leonard (Dave Bautista), Redmond (Rupert Grint), Sabrina (Nikki Amuka-Bird), and Adriane (Abby Quinn) — will be killed by the others and a plague will be unleashed upon the world. The visitors will ask the family for a decision as long as one of them is standing. When no more visitors are left, the apocalypse happens.

These very specific death guidelines put the family in a morally impossible position of watching the world burn or killing someone they love. Because the family chooses not to kill anyone when first asked, tsunamis strike the US’s Pacific Coast. When they don’t give a second answer, a viral outbreak begins. The third plague has planes falling from the sky. Still, Eric and Andrew are skeptical, raising the possibility that the visitors have deluded themselves into believing this outrageous prophecy. (After all, horrible things do happen in our world … kind of a lot.)

Throughout both the cinematic adaptation and the source material, the family tries to escape and the visitors thwart them. In the novel, this comes to a head after the first visitor is sacrificed. Andrew escapes and scrambles to his car to retrieve his gun. He kills Adriane, one of the visitors. In an ensuing scuffle with Leonard, the gun goes off and his child Wen is killed. Her death is an accident, though, and it does not stop the apocalypse.

At the end of the novel, the heartbroken fathers refuse to kill each other, leaving whoever survives entirely alone. After the last visitor kills herself, they drive away with their daughter’s body, unsure of what’s next.

The movie begins to break away from the book after the first sacrifice, and the final sequence of events in the novel does not happen.

In Knock at the Cabin, Andrew does get ahold of his gun. He shoots Sabrina, a different visitor than the one he kills in the novel (the order of the last two visitors’ deaths is also different in the movie). Andrew does scuffle with Leonard. At no point is Wen accidentally shot and killed.

In the movie’s skirmish, Andrew loses control of the gun and Leonard grabs it. Leonard, armed, leads the family to the backyard and asks them a final time if they’ll sacrifice one of their own. The fathers send Wen to a treehouse and tell Leonard they will not kill each other. Leonard tells them that when he dies, they will only have minutes to stop the apocalypse. He kills himself, unleashing the final plague: lightning and fire from the sky.

After Leonard’s death, Andrew and Eric hustle back into the cabin and talk about what they should do next. Andrew says this whole thing is absolutely absurd and that they would never kill each other. But Eric is more convinced by the catastrophes and thinks that he should die to save the world. They go back and forth, only stopping when Eric tells Andrew that Wen needs to have a future. He tells his husband that he sees a timeline in which Wen is grown and Andrew is old, where they both love each other immensely. The scene ends with a gunshot, and cuts to Andrew climbing up the treehouse alone to fetch Wen.

The movie’s ending is more explicit about whether Eric and Andrew save the world

With that drastic change, the endings between the two versions are obviously extremely different. The book sees Andrew and Eric, distraught after the loss of their daughter, pledging to stay together regardless of what happens. In that version, the apocalypse is more ambiguous, due in part to how empty and hopeless Andrew and Eric are after watching their daughter shot to death.

The movie’s ending is much more concrete. Eric and Andrew fulfilled the rules, and therefore Eric’s death should stop the end of the world. And from all appearances, this is exactly what happens.

After the ordeal at the cabin, Andrew takes Wen to the visitors’ abandoned truck and drives to a local diner. There, they see a group of people taking shelter and watching the news. On the broadcast, it appears that the flooding from the first plague, the virus from the second, the airplanes falling from the sky from the third, and the lightning from the fourth plague have simply stopped, all around the world. The newscaster talks about survivors and the diner patrons talk about how all the bad stuff suddenly halted, signaling that the family’s sacrifice saved the world.

That finale is more hopeful, as Eric and Andrew were able to take responsibility for all the bad stuff thrown at them by a vengeful God and save the world, I guess? But I’d argue there’s something just as heroic about not participating in that vengeful God’s game and, like Eric and Andrew in the book, pledging to be together even if it means the end.

The stakes, of course, are intensely altered when there’s a child still in the mix. Wen being alive turns the movie into a choice about Eric and Andrew’s parental responsibility for her and her future. Eric’s choice to sacrifice his life for his child is less complex (it’s a question we’ve seen stories answer before) than the book’s conundrum of having to choose to sacrifice himself after the loss of his daughter and thereby abandoning his husband to an uncertain, terminally depressing future.

The last shot of the movie has Andrew and Wen driving away into the sunset, crisis averted. They both know Eric is a hero and saved billions of people around the planet. Maybe Andrew and Wen will fulfill Eric’s vision of growing old and happy. After the trauma of their home being invaded, watching those home invaders kill themselves, surviving four plagues, and, in Andrew’s case, killing his husband, I hope they fulfill a vision of getting so, so much therapy.