While Martinez and Peel seek to remove Jarvis from power, Sean, Vicky, Sterling and Simon try to stop the release of the virus, and Leila fights for her life. Meanwhile, Earth prepares for the worse as the portal from the alien planet begins to open.

While Sophia struggles with guilt brought on by her decision to commit genocide, Martinez returns to the White House, determined to find the traitors who poisoned him. Meanwhile, Sean and Vicky team up with Simon and Sterling to find Sophia and stop her.

Sterling is forced to turn to Simon for help when they need an antidote for a fallen leader, unaware that Jarvis is scheming to stop them. Meanwhile, Sean and Vicky try to stop the death of thousands, while Sophia uses Leila to fulfill her goal of mankind’s extermination.

When a high-ranking official takes ill in the White House, Sterling and Peel team up to find the people responsible. Meanwhile, Sophia finds herself faced with dissension from within when Michael chooses his daughter over his leader, and Sean and Vicky try to stop Sophia from shipping her weapon from Russia to the U.S.

After negotiations with the sleepers falls through, Martinez asks Senator Lewis to help him find any more of them within the White House, while Sterling tests Agent Simon’s loyalties.

Martinez and Sterling are forced to negotiate with Sophia she gives a graphic demonstration of her group’s technology. Meanwhile, Sean and Vicky travel to France to seek out Dempsey.

Thomas receives a response from his people and summons Sophia and the sleepers to inform them of the news. Meanwhile, Sean forces Vicky to help him, Martinez deals with Vice President Jarvis’ betrayal, and Dempsey continues his plans to acquire aliens for his own experimental purposes.

Martinez and his Chief of Staff order their intelligence departments to determine the nature of Thomas’ message and who it was sent to. Meanwhile, Thomas launches a surprise attack, Alaskan Senator Catherine Lewis threatens to go on national television to alert the public to the enemy among them, and Sean and Leila get a fresh [...]

Martinez and his Chief of Staff order their intelligence departments to determine the nature of Thomas’ message and who it was sent to. Meanwhile, Thomas launches a surprise attack, Alaskan Senator Catherine Lewis threatens to go on national television to alert the public to the enemy among them, and Sean and Leila get a fresh [...]

While Martinez and Blake try to discover the traitor, Thomas launches a new plan that will have earth-shattering consequences. Meanwhile, Sean and Leila try to locate Samantha and evade Dempsey’s mercenaries.