Original air date: 10/14/2018 Runtime: 42:25 min. Diving back into reporting, Kara welcomes new reporter Nia Nal to CatCo in the season four premiere. Meanwhile, James and Lena argue about his impending indictment for acting as the vigilante, Guardian, while Alex and Brainy struggle to get in sync at the DEO. Then, Supergirl is called into action when remnants of the anti-alien terrorist organization Cadmus try to assassinate pro-alien leaders, but their endgame turns out to be much more sinister than she expected. J’onn relishes his peaceful new life, but an outing with an old friend causes him concern.
Original air date: 10/21/2018 Runtime: 42:20 min. A shocking revelation causes chaos in National City. While Alex takes control at the DEO, Supergirl sets out to capture Mercy Graves (recurring guest star RHONA MITRA). Back at CatCo, Kara decides to write an investigative story on Mercy and asks Lena to introduce her as she has ties to the Luthors. Meanwhile, Brainy meets Nia and the two end up in a precarious situation.