Alex starts her first day working with J'onn at The Tower.
Someone tries to kill Andrea, but Kara saves her.
An anti-Obsidian manifesto is delivered to Andrea. They want her to cancel the Obsidian Platinum launch, otherwise they will try to kill more people.
Lena tests Non Nocere on ferocious animals. It works, but she is worried about how it will affect humans. Lex offers setting up a human trial at a prison.
Brainy repurposes Toyman's Immortality Code to use against Leviathan, but he tells Lex that they will need Leviathan's version of Kryptonite to inject it into their skin.
Lex assigns Kara to be Andrea's bodyguard in order to get closer to Leviathan via Andrea's connection to Gemma Cooper.
Kara enlists Alex and J'onn's help in figuring out who is targeting Andrea and why Lex is interested in her.
Gemma accepts Lex's proposition of making Andrea's bodyguard Supergirl.
Lena travels to the prison where many prisoners have volunteered for her trial, including Steve Lomeli.
Alex and J'onn go to the alien bar to ask around about a Chlorophyllian -- a alien who has the same powers as Kara saw trying to kill Andrea.
They get a lead on one and call Brainy to get more information. Brainy find the Chlorophyllian, but lies to them.
Lena runs her trial and it seems to work on the prisoners.
Andrea is attacked again, but Kara saves her.
Steve has a grand mal seizure when his former bully approaches him. He now has the urge to do harm to others.
Alex and J'onn go to the Chlorophyllian's farmhouse. He attacks them and takes J'onn's powers to use against him.
Alex calls for Kara's help and Kara drops Andrea off at the DEO before saving them. The Chlorophyllian, Todd Sapphire, gets away.
Todd was an Obsidian employee who was fired for stealing a pair of Obsidian lenses. He died a year ago, and Kara, Alex, and J'onn figure out that it was his wife, Amy, who attacked Andrea out of revenge for her husband.
Amy attacks CatCo and Obsidian.
Brainy goes to Obsidian to turn off the failsafe so that Amy's power won't cause power outages and explosions across the city.
Andrea uses her powers to transport herself to Obsidian.
Kara convinces Amy to stop and turn herself in.
Andrea digs out her Acrata medallion and smoke comes out of it and engulfs her.
J'onn gives Alex an item from Mars that can tranform into any weapon.
Lena and Lex fix Non Nocere and it works on Steve.
Kara tells William that she wants to go on a date with him.
Lex proposes that he be Obsidian Platinum's global ambassador, and in turn he gets to meet Leviathan.