Camera footage of the attack ends up exposing the President's true identity as an alien. Supergirl saves the President and captures Otis, but Mercy escapes. The duo plan to attack President Marsdin's summit to mark the anniversary of her amnesty act. J'onn believes it to be a hate crime, with the recent rise in anti-alien hatred in the country, although Kara disagrees. Vose, and steal an EMP device from his lab. Brother and sister Otis and Mercy Graves attack an alien, Dr. Kara has stayed busy in her heroic duties working with the D.E.O., and as a reporter at CatCo proving she can multitask. Teleplay by : Gabriel Llanas & Aadrita Mukerji Story by : Robert Rovner & Jessica Queller As Kara mentors a new reporter at CatCo, Nia Nal, and tries to use. 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. They are joined by new cast members Sam Witwer, Nicole Maines, and April Parker Jones. Melissa Benoist stars as Kara, with principal cast members Mehcad Brooks, Chyler Leigh, David Harewood, and Katie McGrath also returning from previous seasons, while Jesse Rath was promoted to the principal cast from his recurring status in season three. The season was ordered in April 2018, and production began that July.
