As Brainiac (Jesse Rath) lays close to death after trying to stop Lex (Jon Cryer), Supergirl (Melissa Benoist) and team soar in to save him, engaging in an epic battle with Gamenmae (guest star Cara Buono). After beating Leviathan, Supergirl turns her attention to Lex (Jon Cryer) who has used the Obsidian platform to brainwash half the world to love him and follow him at all costs, no matter what horrible things he does.
Knowing how dangerous this makes her brother, Lena (Katie McGrath) enlists the entire team - Alex (Chyler Leigh), J'onn (David Harewood), Dreamer (Nicole Maines), Kelly (Azie Tesfai) and Brainiac - to help, but Supergirl realizes that the only way to truly stop Lex is to sacrifice herself.
