*** Spoiler Alert *** The description below contains a lot of info I would consider spoilers, but it is the only description of the episode I can find.
President Martinez makes a triumphant albeit shaky return to the White House, determined to punish the traitors who conspired against him.
Sophia forges ahead with her plan, while battling a new enemy — the guilt that has begun to plague her.
Sean and Vicky form an impromptu team with Sterling and Simon in order to track down Sophia’s headquarters and stop her before the destruction of all human life.
Episode Title - "The Beginning of the End"