DC Studios' Supergirl included the introduction of Argo City as part of her tragic backstory, and what happens next is quite unexpected. Argo City is a key part of Supergirl's origin, serving as her birthplace after Krypton's destruction. In DC lore, Kara's father, Zor-El, made a last-ditch effort to save Krypton by creating a protective dome around the city, allowing this chunk of land to survive as a self-contained fragment in space, which was later named Argo City.
The Milly Alcock-led Supergirl film stayed faithful to the classic comic concept centered around Argo. While it felt like a miracle to sustain a fragment of Krypton in a completely isolated location, the movie confirmed that their survival came at a terrible cost. As it turned out, the separation exposed Kryptonite in the bedrock, slowly poisoning the entire population with radiation and killing Kryptonians one by one. This prompted Zor-El to send Kara to Earth to be with her cousin, Kal-El.
The Arrowverse & DC Comics Explain What Happens to Argo City After Supergirl Leaves
DC Studios' Supergirl movie didn't really explain what happened to Argo City after Kara was sent to Earth. For a location that represents the last remnant of Kryptonian civilization and culture, destroying it off-screen would be a missed opportunity for the DCU. Many claimed that Argo City's future will be explained in a separate DCU project, potentially in Man of Tomorrow or a possible Supergirl sequel. Still, the Arrowverse and DC Comics already revealed what happened to the floating city.
In the Arrowverse, Supergirl Season 3 confirmed that Argo City was not destroyed. It endured, with survivors including Kara's mother, Alura Zor-El, who served on the city's High Council. The Arrowverse's version of Argo also had functioning security forces and Kryptonians thriving, living safely in deep space without being detected. Similar to the Supergirl movie, Argo City had tainted air tied to the Kryptonite. Instead of Alura dying, it was Zor-El who lost his life due to the Kryptonite air.
Season 3 revealed that Argo was able to thrive after the remaining Kryptonians used Harun-El (Black Kryptonite) to help sustain its environment. Still, it faced minor issues, such as the reemergence of childhood diseases. Melissa Benoist's Kara Danvers and Mon-El went to Argo to retrieve some Harun-El so that Lena Luthor can make an antidote for Season 3's big bad, Reign. Kara reunited with her mother, Alura, and successfully convinced the High Council to grant her some Harun-El for their mission.
It wasn't only Kara who discovered Argo City in the Arrowverse. Superman and Lois Lane moved to the hidden city to help Lois navigate her pregnancy. The Crisis on Infinite Earths crossover event, however, confirmed that Argo City was one of the first locations to be destroyed due to the Anti-Monitor's antimatter wave.
Following the reset of realities after the Crisis on Infinite Earths crossover, it was revealed that history had been rewritten. Zor-El, who died in the previous reality, actually survived the destruction of Krypton by escaping into a parallel dimension known as the Survival Zone to save himself. Supergirl Season 6 explored Kara's reunion with her father and their eventual stay on Earth.
DC Comics showcased a similar fate to Argo after Kara left. In the Silver Age continuity, Zor-El, Alura, and some other remaining Kryptonians survive by projecting themselves into the Survival Zone, an alternate reality adjacent to the Phantom Zone. Eventually, they left the Survival Zone and integrated themselves into the Kryptonian bottle city of Kandor - a location tied to Man of Tomorrow's villain, Brainiac.
2008's Brainiac from Action Comics revealed Brainiac's more active role in causing trouble for Argo after the villain tracked down the domed city and killed most of its inhabitants.
In nearly all versions of Supergirl's story, after Kara leaves, Argo City's story as a thriving Kryptonian home concludes, either by mass death from Kryptonite, the Anti-Matter wave from Crisis, or by absorption into Kandor.
Did DCU's Argo City Survive After Kara Left?
2026's Supergirl movie opened up many storytelling opportunities for Argo City after Kara left, even though the film itself presented its fate as tragic and quite final. The last major flashback showed Zor-El making the devastating decision to send Kara and Krypto to Earth. With Alura already gone, the remaining citizens have no real shot at long-term survival.
Still, the film's non-linear flashbacks cleverly set up potential what-if scenarios without contradicting Kara's personal trauma. While it was always portrayed as a doomed lifeboat for remaining Kryptonians, Brainiac's arrival in Man of Tomorrow could hint at his active role in Kryptonian remnants, creating a direct bridge.
In DC Comics, Brainiac has hunted down surviving Kryptonian cities like Argo, and with Kandor City's confirmed ties to the DCU, it's possible that the villain tracked Argo's location and shrank it, integrating it into Kandor. If Brainiac does end up finding Argo, it's possible that he would unexpectedly "save" them by giving them a lifeline through shrinking the domed location.
Doing this would give Kara highly personal stakes in Man of Tomorrow, joining the fight not just to save Earth, but also to save Argo (and retroactively, Kandor) from Brainiac.
