A vast and dangerous anti-alien conspiracy strikes in the first trailer for Supergirl season 4. It seems the people of National City may well have gotten tired of their city being ravaged by battles between powerful aliens.
Supergirl has always been a very socially aware show, and over the course of the last three seasons the series has explored a wide range of social issues. Just days ago, the show officially cast Smallville alumnus Sam Witwer as Agent Liberty, leader of a hate group who believe in human superiority. They're fighting to reclaim their country from humans, and that cause will bring them into head-on collision with Supergirl and her allies. It's not hard to see the real-world metaphors.
The first trailer for Supergirl season 4 has given Agent Liberty the perfect chance to air his sinister ideology. It's a smart trailer, setting the dialogue against scenes from previous seasons and reminding viewers of just how many disasters National City has endured because of various alien invasions. The most disturbing aspect of the trailer, though, is how effortlessly it shifts from shots of the villains to brief clips of the heroes. It's a reminder that Agent Liberty doesn't discriminate between "good" aliens and "bad" ones, and that he's as opposed to Supergirl as he would be to Reign. Perhaps more disturbingly, in Supergirl the president of the United States is herself secretly an alien.
The trailer ends with a stunning glimpse of a Dark Supergirl. Season 3 ended with another Kryptonian pod landing in Russia, and revealed that the person inside was a perfect duplicate for Kara. Showrunners Robert Rovner and Jessica Queller have explained that a major part of season 4's arc will be lifted from the Superman: Red Son comics, which imagined an alternate origin for the Man of Steel in which his pod had landed in Russia. It may be that this Dark Supergirl is assigned to undermine the United States, perhaps by acting as another alien terrorists, perhaps by helping the Children of Liberty. After all, the ideologue could easily justify that to himself, claiming he was "setting a thief to catch a thief."
Fortunately for Kara, she'll have new allies to help in the battle against the Children of Liberty and her mysterious new nemesis. Nicole Maines will be joining the cast as the fledgling superhero Dreamer, the first transgender superhero in film or TV. Meanwhile, David Ajala will be suiting up as the telepathic British antihero Manchester Black. These new friends will hopefully give Kara the edge she needs.