Will Supergirl have to kill Reign to end the Dark Kryptonian threat to Earth? Or will she find another way? Lots of death and destruction in the season finale!

Previously, on SUPERGIRL

It’s been a particularly long wait, getting to the final battle between Supergirl and Reign, and the final battle wasn’t even between Supergirl and Reign. Sure, Kara was there and she was the one that made the victory for the good guys in the season finale possible, but she didn’t throw that final punch to knock out the bad guy.

No, that honor went to Samantha Arias, the human alter ego of Reign, who the Dark Kryptonians were trying to eliminate entirely in order to bring about a terraformed Earth that would be hospitable to the former natives of Krypton. It’s just as dumb as an idea as when I called it out last week. Of course, Sam taking Reign out with a lead pipe leads to a nuclear reaction from Reign, blowing heat vision through Sam, Mon-El and Kara’s mother, Alura, effectively killing a good chunk of the show’s new additions.

That would be a bummer of a way to end the season, but thankfully Supergirl has a plan up her sleeve: use Mon-El’s Legion Flight Ring to go back in time, distract super-powered Sam from stabbing Reign and use the Harun-El, the black rock of Yuda Kal, to bring Sam, Reign and herself into the metaphysical plane, where they eliminate her entirely. And that’s where Sam knocks Reign out, takes her body back and becomes 100 percent human again.

SUPERGIRL‘s season finale borrowed heavily from a number of Superman movies: Kara turns back time to prevent a tragedy, like her cousin did in 1978’s Superman. The Sam/Reign split is evocative of the good Superman/evil Superman battle from Superman III. And, as mentioned last week, the Dark Kryptonian’s plan to terraform the Earth AND the scene where Reign had Kara held down were both reminiscent of 2013’s Man of Steel. It’s the little nods, and the lengths the show runners go to to take some of the sillier aspects of Superman’s legacy and make them work in the context of the show that I really do appreciate.

Speaking of Superman, we FINALLY get some idea of why Clark isn’t making an appearance and helping his cousin and her friends out here. At the beginning of the episode, James Olsen is watching a TV news broadcast that explains that Superman is in Madagascar, fighting the effects of the Kryptonian plot on the other side of the world. A quick comment like that is all I wanted if Big Blue wasn’t going to make an appearance.

The finale offers up a number of other developments:

• J’onn J’onzz’s father, M’yrnn, uses his last act to try and stall Reign so the others can get in position. J’onn decides to honor his father’s last request and “walk among the people,” resigning his post at the DEO and handing the reins over to Alex.

• Brainiac 5 and Saturn Girl returned from the future to help in the fight. Brainy decides to stick around in our present because his “distant relative” – implied to be Brainiac – is making it unsafe for artificial intelligence. In his stead, he convinces Winn to head into the 31st Century. And the two Legionnaires also convince Mon-El to return as well.

• Lena Luthor, fresh off of helping to save Samantha by using the Harun-El and replicating it so Argo City can continue with its survival, is still experimenting with the Black Rock of Yuda Kal. Is she trying to use it for good, or will she become a true Luthor and go too far?

• The biggest reveal, though, comes at the end, when we head out to Siberia. The episode closes on a different version of Kara walking through the snow, probably split by the Black Rock when she helped save Samantha. Are we seeing the origins of Power Girl? Season four should be very interesting.