'Supergirl' Season 3 Finale Ending Explained

Supergirl's third season came to a close tonight, and it ended things with one hell of a cliffhanger.

Major spoilers for tonight's season three finale of Supergirl, "Battles Lost and Won", below!

The episode saw Kara Danvers/Supergirl (Melissa Benoist) and team trying to stop Selena (Anjali Jay), Reign (Odette Annable), and company from taking over the Earth. At first, the altercation didn't go as planned, as Samantha (also Odette Annable) stabbed her evil counterpart in the back, sending her into the Kryptonian pit of lava. As she sank to her death, Reign appeared to kill Sam, Alura (Erica Durance), and Mon-El (Chris Wood) with her laser eyes. Kara panicked, using Mon-El's Legion of Super-Heroes ring to travel back in time to before Sam stabbed Reign. She then used the Harunel to separate Sam and Reign from each other, ultimately killing Reign in a different manner.

But as the episode's final moment showed, Kara's time-traveling actions had some ramifications. (Huh, maybe a certain musical number could've warned Kara about that.)

When Sam, Reign, and Kara all touched the Harunel, it carried a bit of dark energy across the Earth. This was taken to a military base in Siberia, where a group of soldiers stopped a mysterious figure who was approaching them through the snow. It turns out, it was a stoic-looking version of Kara, wrapped in some sort of cloak.

Wait...what?

For DC Comics fans, this will be a familiar sight, as something pretty darn similar happens in Supergirl's New 52 reboot. In 2011's Supergirl #1, Kara's pod is sent to Smallville, but accidentally crashes completely through the Earth's core and is sent to Siberia instead. Kara emerges from her pod, having forgotten that Krypton was destroyed, and is sent on a journey to figure out her situation.

It's a pretty unexpected choice to end the season on this note, especially when this same "The Last Daughter of Krypton" arc was essentially the most prominent appearance of Reign and the Worldkillers. Still, it plunges things into a pretty interesting direction, especially with how Supergirl seems to be handling it.

So, is this new version of Kara a combination of Reign and Supergirl? Or is she just a weird time abberation that resulted from Kara's decision? And either way, what exactly will her goal be -- and how long will it take for her to cross paths with the original Kara? It's too early to tell, but we're pretty excited to find out.

What do you think of Supergirl's season three cliffhanger? Let us know what you think in the comments below.

Supergirl's fourth season will debut Sundays this fall at 8/7c on The CW.