Plot
 | This section's plot summary may be too long or excessively detailed.(December 2015) |
After being taken down by Aunt Astra and her assistants, Kara fights them off. Astra entices Kara to join them but Kara refuses and leaves.
The following morning at CatCo, news has leaked about Cat's e-mail server being hacked, revealing embarrassing messages from Cat. Cat asks Kara to bring in Winn and James for help, but the task is also causing jealousy between Winn and James.
At the same time in another part of the universe, Astra is asked by Non, her Lieutenant and husband, about why she didn't kill Kara, with Astra explaining that she doesn't want to because she is family. At the DEO, Kara and Alex practice on each other during an exercise, but as Kara starts to get more confident in her abilities the more she becomes unfocused as her anger starts to consume her. Alex tells Kara that the DEO should handle the Kryptonian threat from Astra because of family. Alex asks whether she's actually ready to kill if necessary.
In a flashback, Astra goes to meet Kara and tells her niece that Krypton is dying as the core is unstable and that she's trying to save it, but she's had to do some bad things to save the world. Astra then tells Kara that she was leaving the planet, but not before saying goodbye to Kara, only to have this moment interrupted by Alura, who wants to speak with Astra and tells Kara to leave them.
Back in the present day, at CatCo, in a meeting, the board members ask Cat to take a step back and put some distance between herself and the company. After the meeting, Cat tells Kara to keep looking for any more leaks, as she suspects board member Dirk Armstrong is going to find some way to damage Cat's reputation. Kara, using her hearing, listens to Armstrong admitting to having set Cat up. Kara then asks James to enlist Lucy's help in tracking a paper trail to clear Cat's name. Lucy tells them that Armstrong's actions aren't just unethical, but illegal. Suddenly, the three look at a TV set and see Astra hovering above requesting for Kara to talk to her. Kara (as Supergirl) arrives to confront her, which in turn leads to a battle, only to be bested by Astra, who stands over Kara and tells her that Alura was weak and a liar, but Kara says her mother's only weakness was letting Astra live and then resumes the battle but relents after she noticed Astra in tears and falls unconscious. Kara takes Astra back to the DEO.
Winn has found a way to hack into Armstrong's servers and asks James to plant a bug in his office computer. Using a diversion, Kara and James narrowly succeed. Meanwhile, Astra produces a communicator she and Kara used on Krypton and tells her it's time she knew the truth, as she kept the communicator to remind herself of what she was fighting for. She tells Kara that Alura betrayed her, but Kara refuses to believe her Aunt, but then asks whether it was Kara's idea to contact her with the beacon, which is revealed in a flashback when Alura sentenced Astra and Non for murder, despite Astra's plea to save Krypton, and tells her that krypton is on the verge of ecological destruction, but that the Kryptonians won't listen to her. Astra is begging Kara to help but her niece leaves. Kara goes to the hologram to ask if Alura had used her to get Astra arrested, which the hologram confirms (says yes), and whether if Krypton could have been saved if Astra was right, but the hologram repeatedly says it is unable to answer her second question. Kara breaks down crying and tried to destroy the hologram with her heat vision in frustration, saying her mother lied to her.
Back at work, James did find information on financial records that linked Cat to Adam Foster in Opal City, who later them find out is Cat's older son. She sued for custody but she lost then gave up and dropped the lawsuit because she believed that she would be in his life anyway. Cat says that rather than allow Adam to end up in the middle of a media storm, she's going to resign from CatCo. However at the last minute, thanks to Lucy, Winn and James, they managed to provide Cat information on Dirk. Cat confronts Dirk and later Cat fires Dirk and has him arrested. Afterwards, James apologizes to Winn, who tries to downplay his feelings about Kara, and James says to tell Kara his feelings for her.
Back at the DEO, Hank and Alex realized Astra's plan was lose to Supergirl as a diversion, they confront Astra, just in time to inform them that Non and an army of Kryptonians are invading Lord Technologies. When they arrive, Maxwell is ready to greet them with weapons. Meanwhile, Kara goes to Cat, and Kara is surprised to learn that Cat found out that she was Supergirl. Then Kara gets a call from Alex to meet her and DEO and Supergirl arrives to battle with Non and his army.
