The Event

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 worst 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.

While Sterling and Chief of Staff Peel try to identify the traitor within the White House, Sophia continues her campaign. Meanwhile, Leila and Michael rescue Simon, and Sean and Vicky try to track down the courier transporting the sleeper weapon.

Martinez and Sterling receive the results of the blood tests conducted by Senator Lewis. Meanwhile, Sophia continues her search for the super-weapon, Jarvis considers an alliance with an unlikely partner, and Dempsey confronts Sean and Vicky in France.

After the attack on the sleepers, Martinez asks Senator Lewis to help him find any more of them within the White House. Meanwhile, Sterling tests Agent Simon's loyalties, Vicky and Sean track down Dempsey but get a rude surprise, and Sophia announces her new intentions.

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.

Sterling and Richard rally to help President Martinez take control of the political fallout from the detainees' escape from Inostranka. Meanwhile, Michael joins the hunt for Thomas while leaving Leila in the keeping of an old friend, Diane Geller.

While Thomas appeals to the imprisoned Inostranka detainees to join his cause, Sterling attempts to keep them from escaping. Meanwhile, Martinez deals with a recalcitrant Senator Lewis, and Michael informs Leila that she must choose between Sean, or learning the secrets of her bloodline.

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 asks Martinez for information about Inostranka, and Sean and Leila get a fresh lead on Samantha's location.

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.

Dempsey sends his people after Sean and Leila as they try to find Samantha. Meanwhile, Sophia tries to deal with those of her people who disagree with her agenda.

While Martinez interrogates Michael personally, Vicky's superiors send her on a new mission.

While Sophia and Thomas prepare for the next step on their mission, Sterling begins to see conspirators everywhere, including among his own people. Meanwhile, Sean and Madeline seek answers behind Leila's abduction and Michael's coercion.

Martinez and Sterling suspect a traitor when someone within their organization undermines their deal with Thomas. Sean meets up with Madeline, a conspiracy theorist, who is also investigating Leila's disappearance. And Simon must choose when his loyalties to the detainees conflict with his responsibilities as a member of Sterling's team.

While the CDC tries to deal with the captives' contagion, Martinez and Blake try to negotiate with Thomas. Meanwhile, Simon talks to Sophia about Thomas, and Collier closes in on Vicky and Carter.

When Sophia refuses to reveal the detainees' plans, President Martinez tries to get one of the detainees to volunteer information. Meanwhile, Vicky and Carter secure Leila, and FBI Agent Collier begins to suspect that Sean isn't delusional.

President Martinez's staff work diligently to evaluate the situation led in the aftermath of the plane. Meanwhile, Blake Sterling confines Sophia, Sean attempts to convince the FBI of his story, and the alien infiltrator is revealed.

When his girlfriend Leila goes missing during a Caribbean cruise, Sean Walker accidentally uncovers a national conspiracy. Meanwhile, President Elias Martinez decides to release a group of detainees, much to the chagrin of Blake Sterling, the Director of National Intelligence.