There’s a brutal economy to 10 Cloverfield Lane. Most of the film takes place in a claustrophobic bunker underground, in a few rooms, with just three people. The script is tidy and efficient, with almost every tidbit of information serving either as foreshadowing or payoff. When bunker-owner Howard (John Goodman) casually tells a story about using compressed air to freeze and shatter a doorknob, he’s guaranteeing the tactic will be used against him later. A casual comment from his unwelcome guest Emmett (John Gallagher Jr.) about "mutant worms" ravaging the world turns out to be surprisingly prophetic. When the camera lingers meaningfully on a bottle of alcohol in the opening scene, or an IV pole or a shower curtain later on, it’s to establish the tools that are going to become significant as the story progresses. For the first hour at least, 10 Cloverfield Lane is an escape-puzzle game of a movie, where every object and every casual hint may become important later, especially when assembled in unlikely combinations. But the film’s final act has become its biggest sticking point with audiences, in large part because it doesn’t initially seem to progress as economically and logically as the first two acts. Once Howard’s captive Michelle (Mary Elizabeth Winstead) finally outmaneuvers him and escapes, she’s suddenly fighting aliens. Viewers have taken to every available social-media platform to complain about the ending, saying it doesn’t make sense, that it came out of nowhere, and that it ruined the movie. There’s no arguing with personal taste, or with viewers who walked into the film expecting something specific, and were frustrated when they didn’t get it. But the claim that the ending doesn’t fit the movie doesn’t hold water. It takes the story in a radically different direction, and parts of it strain credulity. But ultimately, it only expands on the themes developed in the first two acts. As outsized and strange as the ending is, it still fits precisely with what’s gone before.

10 Cloverfield Lane is fundamentally about domestic abuse. Howard is a classic abuser, to such a degree that his actions run down a straight checklist of common tactics and warning signs. From his first moments with Michelle, he’s more interested in controlling her than comforting her. He has no empathy for her, or understanding of what’s going on in her head. He threatens her with violence when she disobeys his arbitrary rules, then seems baffled a moment later about why she’s upset. He’s jealous and volatile. He terrifies her, then blames her for hurting his feelings by not showing him enough gratitude and respect. He isolates her from her friends and family, both physically, by locking her into the bunker, and emotionally, by repeatedly claiming they’re all dead and there’s no way to even attempt to contact them. (Given that he doesn’t actually know the nature or extent of the attack on the world above, this is one of the earliest signs that he’s nowhere near the altruist he keeps claiming to be.) The ending ramps up the action, but continues the themes Even Howard’s smallest actions fit the standard abuser profile. The way he veers wildly between personality extremes. The way he’s charismatic and easygoing when things are going his way, and even contrite when it suits the story he’s telling. The way he pities himself for the slights against him while lacking sympathy for anyone else. The way he speaks for Michelle without consulting her, telling Emmett to stop joking, because she doesn’t find it funny. Even the way he casually tells Michelle "You’ll learn to love cooking" is chilling. He isn’t just telling her how he expects her to behave, he’s giving her marching orders about how to feel. But above all, he repeatedly gaslights Michelle, starting with their first conversation in the bare concrete room where he’s chained her to a pipe. He starts out by emphasizing, over and over, that he saved her life by pulling her out of the wreck of the car. Even once he’s admitted he deliberately caused that wreck himself, he still returns to his false narrative, screaming "I saved your life!" even when he’s trying to kill her. He doesn’t know what’s going on in the world outside, but he’s allowed himself to believe everyone else is dead because that would justify all of his actions, from a lifetime of paranoia and preparation to his attack on Michelle.

When Michelle escapes the bunker and finds a new threat waiting, this is partially an extension of the abuse metaphor. For victims of domestic abuse, just getting out of the house doesn’t immediately solve all their problems. For the metaphor to stay sound, 10 Cloverfield Lane needs to acknowledge that finding the courage to leave an abuser doesn’t guarantee a happily-ever-after. For a moment, when Michelle first removes her makeshift gas mask and learns that Howard was wrong about the poisonous air, it seems like the movie might end on a note of relief, and the promise that her problems are over. But that would be facile, and would also mean that Michelle had been in a standard slasher movie, where arbitrarily bad things happen to random people, and nothing much is learned. And that wouldn’t be in keeping with the movie’s actual arc, which is all about the way Michelle comes to terms with her abuse. Michelle’s problems didn’t start with Howard, and they don’t end with him. They aren’t imaginary, like the toxic threat, and they aren’t just part of some vague general calamity. They’re specific and personal, and they require a specific, personal catharsis. And that’s the primary reason the big, direct confrontation is necessary in the final act. Michelle’s fight against the aliens completes an arc that began in the film’s opening moments, when she abandons her fiancé after a fight. As she tells Emmett later, she’s had experience with abusers. Her father was one, and her childhood fear and helplessness from dealing with him destroyed her courage. She responds to pressure by buckling and running. It’s unclear whether something significant happened with her fiancé that tapped into her memories of abuse, but for the purpose of the larger story, it doesn’t matter. What matters is that she sees her habit of running as a problem, one she’s ashamed of. That’s the problem that needs to be resolved, more than the problem of Howard’s concrete cage or the possibly imaginary apocalypse. Michelle's problems don't end with Howard because they didn't start with him But just escaping Howard doesn’t solve the problem, because Michelle hasn’t really made a choice: She’s been driven by unavoidable circumstances. Her first actual choice, and the resolution of her arc, comes in the film’s final shot, when she decides to drive to Houston, to fight the alien invasion, rather than to Baton Rouge, to hole up in the "safe zone." That’s a definitive ending. But it’s meaningless if she hasn’t already faced off against the aliens, at least enough to understand the stakes, and commit to her decision in a meaningful way. If her only fights have been the ones against Howard that she didn’t choose for herself, there’s no reason to believe she won’t just run again, as soon as she sees how frightening the alien threat is. Instead, by the end, she’s already faced two aliens, so she knows exactly what she’s getting into by heading to Houston. And it’s the first time her fighting back becomes really meaningful. In the bunker, fleeing initially wasn’t an option, then was the only option. Outside the bunker, the aliens don’t give her a choice any more than Howard did. But both experiences leave her wanting to fight back—and to finally stand up for someone besides herself, like Emmett did, and her brother Colin before him. And even more so, her experiences with both Howard and the aliens have taught her that she has the necessary skills to fight.

One of the things that makes 10 Cloverfield Lane such a surprising, satisfying experience is that from the start, Michelle isn’t a cowering victim, in spite of the later revelations about her history. She’s terrified and injured, and she’s badly thrown when she wakes up chained to a wall. (That chain is one thing Howard never bothers to justify or explain away, which makes it one of the movie’s more interesting touches.) But she’s also resourceful, clever, and determined, and she keeps coming up with creative solutions that also happen to be aggressive ones. She’s always had the strength to fight. It just takes her experiences against different kinds of enemies to convince her of that. Conversely, the presence of actual aliens means that Howard’s bunker isn’t the practical option, but the cowardly one. He’s effectively running away by hiding underground, not contributing to anyone’s safety but his own, and threatening the people he pretends to offer safety. "I wanted to make sure Michelle’s arc wasn’t finished until the very last moments," director Dan Trachtenberg said recently in an io9 interview. "That it didn’t feel like she had a complete story and then something else happened. It felt like when she gets out, now what’s she’s going to do? Which is the thing in life. Whenever you finish something, you still have more to do… It isn’t going into the sunset and everything is going to be okay. In fact, things are going to be potentially worse, but she’s ready to face it. That is the theme of the movie for me." And that theme requires a real, specific threat to work. 10 Cloverfield Lane gets a great deal of its creepiness out of ambiguity, particularly over exactly whether Howard has a sexual interest in Michelle. There are clear arguments for and against, and the film deliberately provides and withholds information to maintain the balance. Still, if the story is being told from Michelle’s point of view, that detail doesn’t matter. To an abuse victim, an abuser’s specific pathology isn’t important; only the results are. Whiplash writer-director Damien Chazelle—who radically rewrote Josh Campbell and Matthew Stuecken’s original treatment for the film—knows what he can leave up to interpretation. As with Whiplash, ultimately it doesn’t matter why the abuser acts out, or how he justifies it. What matters is what the victims do about it, and how they survive. Howard’s characterization isn’t the only crucial change Chazelle made. In Campbell and Stuecken’s original script, there were no aliens, and no final confrontation. According to a detailed script-vs.-script comparison at The Film Stage, in the original version, Michelle escapes the bunker, leaving Howard alive, but with a bullet in his kneecap. She drives toward Chicago, only to find the city destroyed. It’s an impersonal and cynical ending, fitting with the original script’s more impersonal and cynical treatment of Michelle, as more of a bystander and sex object than a hero. The script ends with her simply finding out Howard wasn’t lying. Given his protective nature and her own relative aimlessness, the script almost suggests she made a mistake in leaving the bunker in the first place.

Chazelle’s more dramatic ending certainly stretches believability, as well as the relatively realistic physics that have governed the film up until then. (Michelle surviving, barely bloodied, after the alien drops her vehicle from 30 or 40 feet up, is particularly hard to buy.) It’s certainly understandable that viewers caught up in a believable human drama resisted the sudden shift to a science-fiction action movie with an invulnerable superheroine and a single whiskey bottle capable of taking down a Chinook-sized flying monster. Still, that shift does make sense out of J.J. Abrams’ careful verbiage when he referred to 10 Cloverfield Lane as a "spiritual successor" or "blood relative" to Cloverfield in interview after interview. Abrams was clearly trying to prepare audiences for otherworldly monsters to go with the human drama. And surely 10 Cloverfield Lane should get some points for the sheer ballsiness of that ending, which ramps up the energy and the action instead of letting it trail off to a whimper, and expands the story past a sordid little tale of kidnapping and murder. But ultimately, the ending fits because it’s the necessary completion of a meaningful arc. The film is Michelle’s story. It starts with her, it sympathizes with her throughout, and it dismisses plot points that aren’t related to her story, or important in her character's mind. It doesn’t end with Howard because it was never really about him. It’s about the long-term effects of abuse, and how one person overcomes them. In the end, the aliens aren't as important as the journey they symbolize, and help complete.