A shocking revelation causes chaos in National City. Supergirl sets out to capture Mercy Graves, while Alex takes control at the DEO. Back at CatCo, Kara decides to write an investigative story on Mercy and asks Lena if she can interview her as Mercy has ties to the Luthors. Meanwhile, Brainy meets Nia and the two end up in a precarious situation.
Elenco: Melissa Benoist , Chyler Leigh , David Harewood , Mehcad Brooks , Jeremy Jordan , Katie McGrath , Chris Wood , Jesse Rath , Nicole Maines , Odette Annable , Floriana Lima , Calista Flockhart , Andrea Brooks , Azie Tesfai , Julie Gonzalo , Staz Nair .