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.

When Supergirl needs help, Alex asks Lena and Brainiac to team up. Meanwhile, J’onn questions his decision to quit the DEO. However, after running into Manchester Black, he realizes there are a lot of ways to help his fellow aliens during this tumultuous time.

Everyone gathers for Thanksgiving but Kara is feeling down after her televised debate with Ben Lockwood about the anti-alien sentiment coursing through National City. Meanwhile, James and Lena argue about the best way to handle the Children of Liberty.