Warning: ending spoilers for Jordan Peele’s Us. Read at your own risk.

Jordan Peele’s second directorial project, Us, was a stunning success in its opening weekend. The tremendous box-office response was likely buoyed by memories of Peele’s terrific writing and directing debut Get Out, by an eerie advance marketing campaign, and by strong word of mouth from early screenings. While that early conversation could focus on the film’s unsettling imagery, central metaphor, and ratcheting tension, though, early viewers couldn’t say much about the film’s final startling twist. It requires so much context from the film itself that it’s hard to casually discuss with people who haven’t seen the film, and without the buildup of the movie itself, the intended emotional impact isn’t there. But with the film out in the world, it’s inevitable that viewers are going to want to discuss what happens in the film’s final moments. Above all, that last twist raises questions: does the reveal make any sense? And what does it mean for the story?

The quick summary: in the film, Adelaide Wilson (Lupita Nyong’o) and her family are attacked by doppelgängers who have escaped from a hidden subterranean laboratory. They’re led by Adelaide’s double, Red, who’s also played by Nyong’o. Red explains that the duplicates, known as the Tethered, are soulless copies of people above. They were created in the underground lab in an attempt to control their surface counterparts, and when the experiment failed, they were abandoned. The Tethered have little volition of their own, and are forced to clumsily mimic the behavior of the originals they were created to copy, but Red has led them up into the world to kill the originals and take their places. It’s a metaphor for a divided America of privileged haves and invisible have-nots, Peele says, but the image serves a number of different potential metaphors as well.

At the very end of the film, however, Peele flips the script. He reveals that in childhood, Adelaide and her Tethered counterpart encountered each other in a boardwalk funhouse, and the Tethered version attacked Adelaide, chained her to a bed in the labs below, and took her place up above. The character the audience knows as Adelaide is the lab-created duplicate, and Red, the supposed monster attacking her from below and trying to steal her life, is the original child, trying to reclaim what was taken from her long ago by a supposedly soulless monster.

That’s a startling reversal, and it does entertaining, complicated things to the audience’s sense of empathy and connection with the protagonist. Adelaide is fighting to defend her actual family and her own life, but she’s also fighting to defend a lie, and to keep a world she only gained by assaulting and imprisoning its rightful owner. As an adult, Red is a feral, murderous monster, but in the usual manner of great hero-villain pairs, she’s a monster inextricably linked to, and even created by, the “hero” who defines her. It’s a gut-punch of a revelation that makes it harder to feel any sense of triumph in Adelaide’s success or survival, because it inevitably came at the cost of an innocent life. At the same time, neither Adelaide deserved to be stuck in the underground. Maybe there are no true monsters in Us, just victims. Or maybe both the main protagonist and the antagonist have been made equally monstrous by the circumstances of the world they’re forced to inhabit.

But either way, that ending raises a lot of baffling questions. Peele lays out a little groundwork for the twist early on, when Adelaide returns from the funhouse mute and subdued. Her parents (and the audience) assume she’s deeply traumatized, but she’s actually just a Tethered with no previous exposure to the living world, and she has to gradually learn how to speak and act as a human. In retrospect, there are other potential hints, like the way Adelaide finds her way down to the labs unerringly when she’s trying to find her kidnapped son, Jason. It seems suspiciously easy, the way she makes her way down there — until you realize she’s been there before, that she came from those labs in the first place. Even so, does the twist make any logical sense?

The hardest part of the story to fill in is what Red’s life was like after Adelaide left her in the labs. There seems to be no reason a bright and desperate child couldn’t have found her way back up to the surface eventually, especially since her much more limited Tethered counterpart was able to. The path up to the surface seems complicated, but without significant barriers or pitfalls. Why would original-Adelaide have stayed down below for decades, given the misery down there, and her clear memories of the other world? Most of the Tethered don’t escape because they don’t have Adelaide’s clarity and ambition, but Red is a normal child, with every reason to explore until she finds her way out.

More confusing is the way Red describes her miseries as a Tethered to Adelaide when they confront each other in adulthood. She explains that because of the milestones in Adelaide’s life — meeting her husband, having children, enduring complications with her second pregnancy, having a C-section — Red was forced to go through clumsy mirror images of the same events, taking on the mute, brutish Abraham (Winston Duke, who also plays Adelaide’s affable husband Gabe) as a life partner, and tearing her own body open in order to birth her own damaged version of Jason.

The mechanics of that process are deeply mysterious — why would Red be forced to mimic Adelaide’s activities, instead of the other way around, given that Red is the original? Even assuming that Adelaide was able to bend the Tethered connection enough to claim her own unique life instead of copying Red’s, why would Red be beholden to her in any way? The deeply sad and horrifying implication is that Abraham is stronger than Red, and that in mindlessly going through the motions of mimicking Gabe’s behavior, he raped and impregnated her. But that doesn’t explain why Red would get pregnant at the exact same time as Adelaide, or have the exact same difficulties in birth. It doesn’t explain Peele’s imagery of Red dancing below while Adelaide dances above, as if they were still aware of and duplicating each other.

A lot of this can be hand-waved away with the understanding that Peele doesn’t entirely explain how the Tethered connection works, or what it means. Seemingly the connection goes both ways, even if that doesn’t seem to affect any other “original” human in the story — and given that Adelaide and Red’s situation appears to be unique, it could be enough to argue that it has unique effects on both of them. And an early claim that the Tethered seem to engender big coincidences seems to come to nothing, but maybe it’s a way to explain the ongoing link between Red and Adelaide. The entire idea of the Tethered is based in a metaphor, not a rigorous scientific process. Other aspects of the Tethered are glossed over as well, like who’s cleaning up after and feeding the seemingly infinite lab rabbits they live on, or why the people who designed the experiment would just walk away, leaving thousands of created humans wandering around free on their own.

For the sake of the metaphor, it’s enough to say that Red and Adelaide both live in the same America, where the power structure inherently creates economic splits, and indifferently gifts some people with wealth and comfort, while others are handed privation through no specific faults or choices of their own. It’s a system designed to create suffering, and the privileged are often unaware of how much of that suffering is going on. Everyone in that system is connected in some way, whether they realize it or not. And the twist ending adds a little extra grief, as it’s clear that Adelaide is in some ways woke, and choosing to suppress her class-consciousness. She knows full well that her comfortable, happy life came at someone else’s expense, and that she chose to hold someone else down so she could be free. She’s clearly done her best to deny and forget it, but the understanding that her life is a fragile construct is still lurking under the surface of everything she does.

But even with that understanding, and with the application of a few small, telling details — like the way Adelaide strangles Red when she overcomes her in childhood, apparently damaging her vocal cords and leaving Red with a constricted, squawking voice that carries through into adulthood — the twist still feels like it’s designed for shock value rather than to further the film’s central ideas. It’s problematic not because the questions it raises are insurmountable, but because it’s likely to leave viewers more distracted by the mechanics than caught up in the emotions.

And the twist does undermine one strong, nascent image that seemed on first blush to mean something else entirely. As Adelaide desperately fights back against the Tethered, she comes more and more to resemble Red. In her most extreme moments, snarling and wild-eyed, she looks exactly like her feral counterpart. The explanation, in retrospect, is simple enough — Adelaide is that lab-born monster from the beginning of the movie, and her true nature is leaking out in spite of all the efforts she’s made to curate it away and replace it with something more civilized and acceptable to the world above.

Without the twist ending, that image feels much more telling. In a version of Us where Adelaide and Red didn’t switch places in childhood, Adelaide’s fall into savagery suggests that there’s really no difference between her and the woman she sees as a monster, except the accident of birth. Throughout history, the privileged have always claimed that the underclasses deserve their station because they’re just not suited for better things — that they’re inherently cruder people with less potential, less ability to take advantage of education or appreciate intellectual pursuits. Adelaide’s seeming descent into Tethered-style snarling barbarity feels like a confirmation that there’s nothing really separating Us’ above-ground people from the below-ground people.

And to some degree, that idea still carries out in the story as Peele executed it. Red says the Tethered are soulless, but there’s no indication in Us to say what a soul means. If it’s the ability to love, to feel, and to hope, Adelaide certainly has a soul. She knows enough to want a future she was never invited to have. She’s capable of jealousy, resentment, and fear, but she also seems to authentically love Gabe and their children. She has the capacity for ambition and desire for a better life, even if it means stealing someone else’s life. Us implies that America’s most discarded people are just as human as anyone else living a more comfortable and culturally desirable life, and that neglecting them and letting them suffer is an ongoing act of cruelty that society may come to regret.

And with or without the twist, Us suggests that the answers lie with the next generation, who are increasingly aware of the costs of America’s economic divide. As Adelaide becomes more like Red, her son Jason notices, and is unnerved by what his mother is revealing about herself. She clawed her way to the surface at Red’s expense, and can claim to be a self-made woman. But the price she pays for her choices is alienation from her own son, who has every reason to question who she really is.

It’s clear by the end that Adelaide has won, that she’s hung onto her stolen humanity, even if she’s lost some of it in the process of defending it. It’s less clear what the future holds, whether the Tethered’s new independence will have lasting results, or how the newly developing generation gap between Adelaide and Jason will play out. Peele’s final twist may not entirely play fair with the audience, or with the rules he’s established for this world. But it does carry out his intended message, that the economic and educational divides in America are difficult to cross without significant cost, and that they hurt people on both sides of the line. And it implies something even darker: in America, the best way to get ahead — maybe the only way, for people not coincidentally born into power — is to be amoral, ruthless, and absolutely willing to steal and even kill in defense of whatever luxuries we can get.