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.
Original air date: 10/28/2018 Runtime: 40:55 min. Ben Lockwood (SAM WITWER) didn’t always hate aliens. Through a series of incidents, and input from his anti-alien father (guest star XANDER BERKELEY), Ben slowly transforms from a mild-mannered professor into the villainous Agent Liberty to today.
Original air date: 11/04/2018 Runtime: 42:14 min. When Supergirl needs help, Alex asks Lena and Brainiac to team up. Meanwhile, J’onn questions his decision to quit the DEO. However, after running into Manchester Black (guest star DAVID AYALA), he realizes there are a lot of ways to help his fellow aliens during this tumultuous time.
Original air date: 11/11/2018 Runtime: 42:23 min. Colonel Haley (new series regular APRIL PARKER JONES) makes a surprising decision regarding Supergirl. Meanwhile, Kara writes a series of articles highlighting aliens in National City in the hopes that humans will stop being so fearful of them. Unfortunately, the articles put some of the aliens in harm’s way.
Original air date: 11/18/2018 Runtime: 42:23 min. Although everyone gathers for Thanksgiving, Kara is feeling down after her televised debate with Ben Lockwood about the anti-alien sentiment coursing through National City. Meanwhile, James and Lena argue about the best way to handle the Children of Liberty.
Original air date: 11/25/2018 Runtime: 42:23 min. James falls in deeper with the Children of Liberty in his efforts to meet Agent Liberty. Meanwhile, Supergirl and Manchester Black follow a lead on Agent Liberty’s location, but things take a dark turn. And Lena kicks off her first set of trials. Chad Lowe directs.
Original air date: 12/02/2018 Runtime: 42:22 min. In the midseason finale, Nia has a powerful dream about Agent Liberty, but refuses to look at it as a prophetic dream and pushes it aside. After noticing something is bothering Nia, Kara enlists Brainy’s help, and the two try to persuade Nia to embrace her destiny. Meanwhile, Manchester Black pays Ben Lockwood a menacing visit. Kevin Smith directs.
Original air date: 01/27/2019 Runtime: 42:20 min. Kara joins Nia on a trip to Nia’s hometown to visit her family during the town’s annual Harvest Festival. While home, Nia’s mother, Isabel (guest star KATE BURTON), encourages her daughter to embrace her destiny. Meanwhile, Alex deals with a dangerous street drug that is turning people violent and giving them temporary superpowers.
Original air date: 02/17/2019 Runtime: 42:25 min. With his P.I. shingle newly hung outside his office, J’onn welcomes new clients. Trying to take her mind off what happened at the DEO, Kara decides to team up with J’onn on his latest assignment, which unfortunately ends up tying directly into Alex’s current investigation that involves the villain Menagerie (guest star JESSICA MERAZ). Meanwhile, Lena shares some news with James, but his reaction isn’t what she expected. Nia invites Brainy to her Valentine’s Day party.