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…

Supergirl, Alex, and Brainiac thwart an alien attack while William investigates Kara. J’onn J’onzz and Kelly use Obsidian tech to solve a problem.

Crowley is worried about Dean getting out of control, giving him a target to feed the mark. Sam struggles to escape from Cole. Hannah tries to convince Metatron to give…