Birthdays aren’t always cheerful, especially when your past is filled with trauma, and your family and home are long gone. Such is the grim reality for Kara Zor-El, portrayed by Milly Alcock in “Supergirl.” Her introduction is nothing short of a booze-fueled spiral, as she hops from one dive bar to another across red-sunned planets, desperately grasping for any emotion as her 23rd birthday looms. Ignoring calls from her cousin Clark, played by David Corenswet, she finds herself in a haze, barely awake in the most awkward places, while her faithful companion, Krypto, adds an uncouth touch to her spaceship surroundings. Yet, destiny intervenes when Kara encounters a girl armed with a sword and fiery vengeance, setting Kara on an unexpected path across the galaxy spurred by lingering heroic instincts.

By the conclusion of “Supergirl,” a transformed Kara emerges victorious, no longer just an intoxicated 23-year-old but rather the beacon of hope her cousin always believed she could become. In the film’s triumphant final moments, she overcomes her greatest adversary—despair—proving no villain can dim her newfound light.

Though “Supergirl” might not break new ground in the superhero space opera realm, with its rather generic sci-fi henchmen and planets indistinguishable beneath layers of brown rockiness and dingy colonial motifs, the film finds its strength through its cast. Milly Alcock brings a radiant energy to Kara’s role, guiding her through a narrative that, while familiar, is executed with enough finesse to grip viewers until the thrilling finale. Her journey from despair to hope is the real epic battle fought in this cosmic setting.

Here’s what you might have overlooked on Kara’s journey and the ending that redefines her legacy in “Supergirl.”

The movie kicks off with Kara’s grungy adventure through a series of interstellar bars, aiming to drown her sorrows in cheap drinks alongside some dubious space cereal. Her constant companion in these escapades is Krypto, whose loyalty and love prove grounding for Kara. Her world takes a lethal twist when a skirmish with the notorious brigands known as the Brigands results in Krypto being shot with a poison dart. This tragic turn of events propels Kara on a relentless quest to retrieve the antidote, with the grim countdown of three days before Krypto succumbs to the poison.

Kara meets another dependent in the form of Ruthye (Eve Ridley), a girl seeking revenge against the Brigands and their leader, Krem of the Yellow Hills (Matthias Schoenaerts), which Kara discourages. Ruthye’s father (Ferdinand Kingsley), a noted swordsmith, is killed, along with her mother (Emily Piggford) and brother (Emond Knoll). 

What follows is a standard chain of action set pieces, betrayals, and reveals. The pair survive an attack on their space bus, and they encounter the infamous spacefaring mercenary Lobo (Jason Momoa) on planet Bilquis, who’s also seeking the Brigands. The pirates attack in search of more “brides” to keep their all-male bloodline going, and Kara and Lobo fight them off. When the Brigands escape, Kara threatens local information into taking her to their base of operations, which turns out to be a planet oscillating between green and yellow suns, the former of which nearly kills her. When all hope seems lost, Ruthye emerges, having gone against Kara’s wishes, and drags her to safety.

The final act of “Supergirl” takes place almost entirely on the planet Barenton, where Krem has left his flagship between raids. The planet exists under both a yellow sun and green sun, with the green having an effect on Kara similar to Kryptonite (which is explained more thoroughly in the “Supergirl: Woman of Tomorrow” comic series the film is based on).

After Ruthye drags Kara to a cave for safety, she goes out in search of water but is captured by the Brigands. In their ship, Ruthye encounters Lobo again, who has also been captured. The two escape, but Ruthye is caught again on the ship’s deck by Krem. Thankfully, the green sun sets and the yellow sun rises, and Supergirl emerges in full costume (delivered to the planet by Ruthye) to wreck shop.

In short order, and with a little help from Lobo, Kara dispatches the Brigands and saves the women they abducted. When Ruthye has a chance to kill Krem and avenge her slain family, Kara persuades her to let it go. After Ruthye walks away, Kara kills Krem herself. They then return to Krypto with the antidote and save him. After a tearful goodbye with Ruthye, Kara goes back to Superman to say that she’s done bouncing around the galaxy, and is ready to stay in one place for a while and be the hero he knew she was.

Throughout “Supergirl,” but especially at the end, Kara’s transformation into a true hero is all about protecting the helpless. She takes clear joy in beating up cronies earlier in the film for the sake of it, but gets a hard jolt during the battle on Bilquis when Krem kills a whole family in front of her. Ashamed and guilt-ridden, Kara pursues him alone, even though the plan is reckless.

In the final battle on Barenton, much of the action is framed around Ruthye. It’s like we’re seeing Kara in her full glory from the girl’s perspective. While Ruthye brandishes her sword many times during the battle, Kara always jumps in right before she strikes. Not only does she protect her, but she keeps her from committing the kind of violence Kara is familiar with.

This desire to “save” Ruthye extends to the confrontation with Krem. Kara and Ruthye bond over their shared loss of home and family, which Kara tells her can’t be cured by simple revenge that could leave Ruthye worse off in the long run. By killing Krem herself, she steers Ruthye clear from future harm, but she also shields her from the burden of having killed a man in cold blood. Like her cousin, Kara’s moral root is that of a protector. And yes, she saves the captured women, too.

Jason Momoa’s public love of Lobo came full circle when he was formally cast in “Supergirl.” The addition also helped realize part of the original plan for the “Woman of Tomorrow” comic. According to writer Tom King, the initial vision for the series was inspired by “True Grit,” with Supergirl and Lobo acting as differing role models to the young Ruthye. Lobo was cut from the comic, though most other core details are adapted faithfully in the film (artist Bilquis Evely even gets two planets named after her).

While Momoa kills it in the role and the character’s inclusion makes good on the original comic pitch, Lobo feels a bit out of place in the movie. He is given little development and an extremely convenient connection to Kara’s request that avoids any real dynamic between the two. Lobo’s powers and abilities are on full display, though, and he uses them to great effect to help Kara in the climax.

After Kara lays waste to the Brigands, there’s a distant shot of Lobo watching from afar, cigar chomped between his teeth, nodding in approval. It’s a shame they don’t spend more time together, but Momoa has made it clear that he wants to return to the role in a bigger way. As of yet, there are no such confirmed plans, but the character’s introduction to the DCU is as a helpful antihero leaves many possibilites.

In flashbacks to the fall of Krypton, Kara’s mother urges her to be good, but clarifies that it doesn’t always mean to be nice. Later, when Kara is suffering beneath the glow of the green sun, Ruthye says something similar — that Kara is not always nice, but she is kind.

That distinction is one of the core thematic principles of the film. Kara’s crudeness and willingness to embrace temporary darkness for the greater good are a stark contrast to Superman, and even when she rises in full garb at the end — arguably the best Supergirl has ever looked in live-action, by the way — she maintains her edge. What could have been a generic story about the dangers of revenge becomes a more nuanced tale of how tragedy changes you, all because Kara, unlike her cousin, is willing (and even a bit invigorated) to kill Krem.

At one point, about midway through the story, Kara describes Clark as being “younger” than her, even though he is about a decade older. When Ruthye asks what she means, Kara says that his heart is lighter, because he never experienced the kinds of things that Kara, and now Ruthye, have gone through.

There is no confusion as to what “Supergirl” is about. The film hits its main theme repeatedly, but most powerfully in the quiet moments between Kara and Ruthye. Their conversation on Bilquis, when Kara explains the fall of Krypton, is a much-needed respite in the midst of a breakneck plot, and it’s where Kara delivers the film’s big treatise on grief.

After telling her story, Kara urges Ruthye to reconsider her revenge plot, saying that loss and grief can push you to all kinds of dark places and revenge won’t make it better. It’s a nice sentiment, but Ruthye cuts through it almost instantly, asking Kara when she finally stopped being angry about what happened to her. In a prestige moment of her performance, Milly Alcock scoffs quietly, and then, as much to herself as to the girl, responds, “Any day now.”

Even when she returns to Earth, it’s clear her journey isn’t over. She has made the first major step of choosing to become something greater than her grief, but the work is ongoing, and the film thankfully doesn’t judge her for her continued bouts of fury. By taking on the burden of killing Krem, Kara allows Ruthye to return to her life in peace. We are told that she will live with her aunt, and plans to take up her father’s craft of making swords. Hopefully, she will rarely have to use them.

While the grief theme is thoroughly explored in “Supergirl,” the film unfortunately doesn’t spend as much time on its other interesting ideas. There’s a brief nod to the inherent sexism in Superman being a “man” and Supergirl being a “girl” — an idea intrinsically questioned by the title of the source material, “Supergirl: Woman of Tomorrow.” When it’s revealed that the Brigands are kidnapping girls to be their “brides,” it seems like the film might engage deeper with its inherently gendered themes.

What we get instead is standard superhero action, with almost no time paid to how the specific crimes of the Brigands might resonate with Kara or Ruthye. While a female superhero movie is not required to engage in gender politics, it feels odd that “Supergirl” puts so much emphasis on explicitly gendered violence, only to dodge it.

There’s some more interesting material in how age and maturity aren’t directly linked. Though she is young, Kara carries the weight of a dead race with her. She carries her father’s pocket watch, adding to the running theme of time, but again, the film doesn’t pull these threads together. You can read the character as a person out of time, with a three-day deadline to save Krypto yanking her back in a visceral way. But the film spends so much time on CGI battles and plot-centric dialogue that these ideas don’t get space to breathe.

In a May 2026 interview with Variety, Milly Alcock discussed how Kara’s arc in “Supergirl” is symbolized by her finally putting on the costume. “She realizes that being Supergirl has nothing to do with her and has to do with everybody else around her,” the actress said. “She needs to put her own feelings aside to help others, and through that she can save herself. So that’s what the suit is for her.” Kara finally returning to Earth in full costume, matching her cousin, closes out the journey nicely.

Director Craig Gillespie shared similar sentiments with The Playlist. “Bizarrely, sort of miraculously, through her journey with Ruthye, whom she’s helping along the way very reluctantly, she realizes it’s almost like holding a mirror up to herself,” he explained. The director elaborated on the similarities with his previous films, like “Cruella” and “I, Tonya,” in their depictions of complicated women. “I’ve gotten into this section of very strong female characters that are flawed and human and overcoming obstacles. It’s a space that I love to be in.”

For Eve Ridley, the production helped their arcs click into place by the third act. “I think it was really lovely to see [Ruthye and Kara’s bond] over time because the film was shot in chronological order,” Ridley told SciFiNow, “so as our characters developed, my and Milly’s relationship also developed … it was definitely very fun to shoot in that way.”

Kara’s return to Metropolis at the end of Supergirl shows that she is finally ready to heal. That’s not the same as healing. Her grief still burns, but she’s done running from it and drowning her sorrows in self-destructive behavior. Putting on the costume in the third act, which she initially tells Ruthye doesn’t have any special powers or meaning, itself signals her growth.

Beyond the character arc, there are also implications for the larger DCU story. Having two Kryptonians on Earth is a huge boon for the human race, and with Brainiac as the main villain in James Gunn’s upcoming “Man of Tomorrow,” the planet will likely need them both. The “Superman” sequel is currently scheduled for a theatrical release on July 9, 2027, and Supergirl is confirmed to be a part of it.

Gunn’s DC Universe timeline has a lot more on the docket, but we don’t know yet if Kara will get a proper sequel outside of her appearance in “Man of Tomorrow.” The critical response to “Supergirl” has been pretty mixed, and the likely merger between Warner Bros. Discovery and Paramount Skydance could have looming implications for the DCU as a whole, should the deal go through. At the very least, we’ll see Alcock put on the cape and boots once more in 2027.