You probably went into the theater expecting a classic, wholesome "Girl of Steel." Instead, you got a hungover Kryptonian calling Superman a "b*tch" while stumbling through the Fortress of Solitude.
It was wild. Honestly, I didn't see that coming, even with James Gunn’s track record for subverting expectations.
When Milly Alcock’s Supergirl finally crashed into the frame during the final minutes of Superman (2025), it wasn't just a fun cameo. It was a massive tonal shift for the DCU. She didn't float down gracefully. She literally forgot where the door was and smashed through a wall, looking for her dog.
The Fortress of Solitude Cameo Explained
If you were confused by why Kara Zor-El looked like she just crawled out of a dive bar, you aren't alone. Clark Kent basically has to explain the whole thing to "Gary" (the robot formerly known as Number Four) and the audience.
Kryptonians can’t get drunk on Earth. Our yellow sun makes their metabolism too efficient. To actually feel a buzz, Kara has to fly to star systems with red suns—like Krypton’s old sun—where she loses her powers and becomes "vulnerable."
It’s her way of coping.
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While Clark was raised by the Kents in a pile of hay and wholesome life lessons, Kara was 14 when Krypton exploded. She watched everyone she knew die. She lived on a drifting, radioactive "chunk" of the planet for years before making it to Earth. She’s jaded. She’s traumatized. She’s a "total mess," as Gunn puts it.
Krypto Isn’t Actually Clark’s Dog
This was the biggest "aha!" moment for many. Throughout the movie, Superman keeps calling Krypto’s presence a "foster situation." He tells Lois it’s just a dog he’s watching.
When Kara shows up to retrieve him, we realize why the dog is so poorly behaved. She loves that he's a "messy, ill-mannered ruffian." She cackles with delight when he tackles her to the ground.
Superman has been babysitting his cousin's pet while she's been off partying on the edge of the galaxy. It’s a hilarious reversal of the usual "perfect superhero family" trope.
Setting Up Supergirl (2026)
That two-minute scene is a direct bridge to her solo film, Supergirl, which hits theaters June 26, 2026.
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Directed by Craig Gillespie (the guy behind I, Tonya and Cruella), the movie is heavily based on the Tom King comic Supergirl: Woman of Tomorrow. In that story, Kara’s 21st birthday trip to a red-sun planet gets interrupted by a young girl named Ruthye (played by Eve Ridley), who wants to hire Supergirl as an assassin to avenge her father.
Why Milly Alcock is the Perfect Choice
Gunn has been vocal about why he chose Alcock. He wanted someone "pixie-ish but with attitude." After seeing her as Rhaenyra Targaryen in House of the Dragon, he was sold on her ability to play "edge" and "grace" simultaneously.
She isn't playing the "female version of Superman." This isn't the earnest, sunny Kara we saw with Melissa Benoist. This is a space-western antihero.
Who Else is Joining the Fray?
The 2026 movie is filling out its cast in some pretty interesting ways. We know Matthias Schoenaerts is playing the villain, Krem of the Yellow Hills. But the biggest shocker? Jason Momoa is Lobo. Forget Aquaman. Momoa is finally playing the foul-mouthed, interstellar bounty hunter he was born to play. Having him cross paths with a depressed, hard-drinking Supergirl sounds like a recipe for absolute chaos.
We also know David Corenswet’s Superman will return for at least one "all-Kryptonian" scene. Alcock recently teased that they filmed a sequence speaking the Kryptonian language, which sounds like it’ll be an emotional gut-punch regarding their shared heritage.
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The Big Takeaway
What most people get wrong about Supergirl in this new universe is assuming she’s a sidekick. She’s not. She might actually be more powerful—or at least more dangerous—than her cousin because she has nothing left to lose.
If you want to prepare for the 2026 film, go read Supergirl: Woman of Tomorrow by Tom King and Bilquis Evely. It’s only eight issues, and it’s basically the blueprint for everything we saw in the Superman cameo.
Keep an eye out for the first full trailer dropping soon. From the teasers we’ve seen, the tone is going to be "desolate cosmos" meets "epic sci-fi," which is a far cry from the hopeful streets of Metropolis.
Actionable Next Steps:
- Read the Source Material: Pick up the Supergirl: Woman of Tomorrow trade paperback to understand the "jaded" Kara.
- Re-watch the Superman Ending: Pay attention to the background details in the Fortress of Solitude; there are hints about Kara's travels hidden in the set design.
- Track the Production: Filming is currently moving through the UK, so watch for set leaks involving Momoa's Lobo.