The Supergirl season 3 finale featured some major moments and set up and iconic comic book storyline to unfold during season 4…
The Supergirl season 3 finale featured plenty of twists and turns as the Worldkiller storyline came to an end, a couple of prominent cast members said goodbye and there was at least one teaser for what lies ahead in season 4.
First let’s wrap up what happened in the season 3 finale….
Supergirl was able to defeat Reign but she originally tossed the Worldkiller in a cauldron that melted her and before dying she unleashed a powerful blast from her heat vision, cutting down Mon-El, Sam and her mother so Kara was forced to use the Legion of Superheroes ring to travel back in time to reset this fight to get it right the second time around.
In the end, Supergirl defeated Reign thanks to that cosmic rock that she got from her home planet, Sam stayed alive and her mother was able to travel back to Argo with three prisoners in tow, who attempted to create New Krypton on Earth.
In the aftermath, Sam was reunited with her daughter Ruby but as of now Odette Annable isn’t slated to return to Supergirl for season 4, although that could change.
J’onn said goodbye to his father, who sacrificed himself to stop Reign from destroying the Earth’s core in an attempt to resurrect Krypton. Following his death, J’onn decided he wanted to spend more time amongst the people of Earth rather than be secluded inside the DEO any longer so he gave up his post as director.
In turn, J’onn handed over the reins to Alex, who was contemplating her own step back from active duty while she contemplates starting a family of her own. J’onn makes Alex the new director of the DEO, which will allow her to stay out of the action as much but still maintain her role with the organization.
Meanwhile, Brainy and Imra returned from the future to help stop Reign but they also come along with some unfortunate news.
Defeating the Worldkillers stopped Pestilence from unleashing the Blight on the future, which means millions of people don’t die but that change in the timeline also stopped one very major person from being killed during that fight. One of Brainiac-5’s relatives survived the Blight and now they’ve made Earth uninhabitable for all the other beings using artificial intelligence.
That means Brainy can’t return to the future so he has to ask Winn to replace him on the Legion of Superheroes. According to Brainy, a discovery that Winn made in 2018 will come to be one of the most important pieces of science in the future so he asks him to go back with the Legion to help them defeat his evil relative. Winn agrees and decides to return to the future with the Legion.
The same could be said for Mon-El, who ultimately decides that his place is back in the future where he created a life for himself and an important job as one of the Legion of Superheroes. With that, Mon-El, Imra and Winn hop on the Legion ship bound for the future, which explains why Christopher Wood won’t be returning for Supergirl season 4 and Jeremy Jordan will be dropping down to recurring status for next season.
“The plan for Chris was always to have him on the show for two years,” executive producer Robert Rovner told TVLine about Wood’s exit from the show. “We’ve loved telling Mon-El’s story, as well as the story we’ve told for him and Kara. We hope the fans felt that it was a satisfying conclusion.”
As of now there are no plans to bring Wood back to the show but that could change in the future.
We do know that Jesse Rath, who plays Brainiac-5 has been added as a full time cast member for Supergirl season 4.
As far as the other major characters — James Olsen outed himself as Guardian before the finale came to a close so that will certainly set up a big story for him in season 4. As for Lena Luthor, she has secretly been working with that same Kryptonian rock that helped stop Reign and she’s continuing her experimentation. Lena hasn’t gone full villain yet but she may be well on her way.
The big tease for season 4 that was set up at the end of the episode was actually an homage to a famous comic book storyline involving Superman that was written by Mark Millar.
During the final fight, Supergirl used that Kryptonian rock to separate Reign from Sam one last time before putting an end to the Worldkiller once and for all. What Supergirl didn’t notice was that the rock also separated her into two parts, sending another one halfway around the globe where she landed in Siberia.
The end of the episode showed a Supergirl doppelganger appearing out of the snow, looking confused as she arrives at a Soviet military base. Following the finale, the executive producers behind Supergirl confirmed that they will be doing a story somewhat based upon the alternate universe story ‘Superman: Red Son’, which theorized what would happen if Superman’s pod from Krypton crash landed in Russia rather than Kansas.
“For fans of the comics, I think they might recognize that the story we want to tell is inspired by the iconic DC Comics’ Red Son, which told an alternate origin story for Superman,” Rovner said. “What happened if — as a baby — Superman landed in Russia and became a hero there instead of in America. It’s an homage to that.”
When Supergirl returns in the fall, the show will shift to its new night where it will air on Sundays at 8pm on the CW.