'Supergirl' Comic-Con Trailer Released at SDCC

Supergirl's third season ended with a shocking reveal and now we have our first look at what comes next in The CW series' fourth season.

The CW has released the official Comic-Con trailer for Supergirl's upcoming fourth season which debuted during the show's San Diego Comic-Con panel. While most of the footage was culled from season three, there are a few interesting shots at what appears to be a new suit for Supergirl as well as an ominous voiceover by Agent Liberty (Sam Witwer). You can check it out in the video above!

As fans of the series will recall, Supergirl's third season ended with J'onn (David Harewood) stepping down as director of the DEO, Winn (Jeremy Jordan) going with the Legion of Superheroes into the future, and perhaps most shockingly, an alternate version of Kara (Melissa Benoist) popping up in Siberia. It turns out that this alt-Kara's appearance -- complete with the appearance of military men who spotted her walking towards them -- was a very deliberate reference to the 2003 Superman: Red Son miniseries by DC Comics.

"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," showrunner Robert Rovner told TV Line.

"What happened if -- as a baby -- Superman landed in Russia and became a here there instead of in America?" showrunner Jessica Queller added. "It's an homage to that."

That homage will include the introduction of some new characters, including Agent Liberty, played by Sam Witwer. Witwer is probably best known by DC fans from his role as Smallville's Davis Bloome/Doomsday, making him the latest Smallville alumni to join the ranks of Supergirl after Laura Vandervoort and Erica Durance.

"We love it, and we think the fans love it," showrunner Robert Rovner said of the show's legacy casting last year. "We love seeing people that we know and are familiar with step into other roles. And what's great about them is that they're all wonderful actors as well. So, you get the excitement of seeing them in the new role, but they also bring a lot when they take on these new characters."

What do you think of this first look at Supergirl's fourth season? Let us know your thoughts in the comments below.

The fourth season of Supergirl will debut on Sunday, October 14th, at 8/7c on The CW.