In season four, Supergirl is facing a bigger threat than she's ever faced before – a new wave of anti-alien sentiment, spreading across National City that’s fomented by Agent Liberty. As Kara mentors a new reporter at CatCo, Nia Nal, and tries to use the power of the press to shine a light on the issues threatening to tear the city apart, Supergirl takes to the skies to battle the many villains who rise up in this era of divisiveness.