Kara goes toe-to-toe with Astra when her aunt challenges Kara’s beliefs about her mother. Also, Cat is threatened with being removed as the CEO of CatCo after a hacker exposes her private and damaging emails.
After being taken down by Aunt Astra and her assistants, Kara fights them off, as Astra informs her niece that she has found a way to counter the Kryptonite with devices strapped to them so they won't be weakened. Astra entices Kara to join them but Kara refuses and leaves. She then returns to the D.E.O. to inform Alex and Hank, but they don't want Kara to rush back for now and suggests she gets some rest, with Alex informing Kara to trust Hank for now. The following morning at CatCo, news has leaked about Cat's e-mail server being hacked, revealing embarrassing messages from Cat that are damaging even her lawyers are suggesting that she should not make matters worse. As Kara tells Cat that this issue will be resolved, Cat calls for a meeting and asks the board to go through her e-mails for anything incriminating. Cat also asks Kara to bring in Winn and James for help as the leaked e-mails become front page news at The Daily Planet, but the task is also causing jealousy between Winn and James, not to mention Kara as well.
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, but adds "I will die before I allow another world to end before I can save it." At the D.E.O., Kara and Alex practices 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 chides her for hesitating, then tells Kara that the D.E.O. should handle the Kryptonian threat from Astra because of family. Alex asks whether she's actually ready to kill if necessary, and Kara says that Superman doesn't kill, but it won't work for Astra.
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 her twin sister and tells Kara to leave them.
Back in the present day, Cat is relieved that there was no evidence of anything to slander her after Kara and James informed her, but at the meeting the board members ask her 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 if their hunch is right, Armstrong could potentially face criminal charges. 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 that resulted in Supergirl preventing debris from killing innocent bystanders, 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 D.E.O., where Alex says they'll call her when Astra wakes up, but Kara turns that down.
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 succeeds, and when Dirk returns he sees James at his desk, saying he'll support him if Cat leaves. 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 Earth is on the verge of ecological destruction, but that the humans won't listen to her. Astra is begging Kara to help but her niece leaves, and Astra says she loves her. Kara goes to the hologram to ask if Alura had used her to get Astra arrested, which the hologram confirms, and whether 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 destroys the hologram with her heat vision in frustration, saying her mother lied to her. Alex tells her that she doesn't know what really happened, and Kara says that she knows both she and Astra "were given life sentences by my mother."
Back at work, Kara refused to discuss the issue with James and Winn, but James did find information on financial records that linked Cat to Adam Foster in Opal City, who James and Winn think she been paying money to, but when Kara goes to see Cat, she reveals that Adam is her son and his father was somebody she hadn't dated in a while. 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, but she determined that her child might be better off without her. Cat says she stopped asking herself that decision years ago and admits her regret. She 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 in her office with the evidence. Dirk admits to the hacking, but initially threatens to fight. However, since Dirk used the company's computers to hack Cat's e-mails so he can take over the company, he doesn't have a leg to stand on. Cat fires Dirk and has him arrested. Afterwards, Kara steps away as James apologizes to Winn, who tries to downplay his feelings about Kara, but James says he's not in Winn's way, and that if he has feeling for Kara, he should tell her and reminds Winn that Kara is special, not because she's Supergirl, she's worth risking it for and he should try.
Back at the D.E.O., Hank asked Alex about Kara. Hank is unable to read Astra's mind; Kryptonians are immune to his telepathy. However, they suspect something is amiss when they see footage of Astra stepping over Kara. Knowing that Astra has been a warrior all her life, they find it hard to believe she would put herself in sch a position. Suspecting that Astra wanted to 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 Technogies. When they arrive, Maxwell is ready to greet them with weapons, but they're no match for the kryptonite-immune invaders. Meanwhile, Kara goes to Cat, and Kara is surprised to learn that Cat found out that she was Supergirl, having figured out the recent encounters whenever they were around. She tells her to take off her glasses, and thanks her for all the help she's given her, calling her Supergirl. When Kara gets a call from Alex, she excuses herself to help the others fight Non and his army, with Hank using his powers to disable one of the Kryptonians' shields to weaken him after he found out Hank wasn't human. Kara suddenly arrives and is ready to battle Non.
- Cat Grant refers to Winn Schott as "hobbit", a reference to the novel The Hobbit, written by J.R.R. Tolkien.
- Two of Non's henchmen from the climatic battle possess powers, and some physical features, abundantly similar to Riot and Fright.
|Supergirl season 1|
|"Pilot" • "Stronger Together" • "Fight or Flight" • "Livewire" • "How Does She Do It?" • "Red Faced" • "Human For a Day" • "Hostile Takeover" • "Blood Bonds" • "Childish Things" • "Strange Visitor From Another Planet" • "Bizarro" • "For the Girl Who Has Everything" • "Truth, Justice and the American Way" • "Solitude" • "Falling" • "Manhunter" • "Worlds Finest" • "Myriad" • "Better Angels"|