The Event

After his girlfriend mysteriously disappears from a cruise, Sean Walker discovers a conspiracy of global proportions.

The president's staff grapples with a new reality; the conspiracy engulfs an FBI agent and a mercenary with questionable ties; a shadowy figure emerges with knowledge of the detainees.

The administration unveils a tough new strategy to force Sophia to reveal the detainees' plan; Vicky and Carter possess a crucial hostage.

The White House grapples with a mysterious biological threat. Their only hope is to crack Sophia during interrogation. Meanwhile, Vicky and Carter keep their hostage captive while they await further instructions. FBI Agent Collier, on her search for Leila, stumbles upon Vicky's secret life. Elsewhere, a powerful businessman, Dempsey with classified intelligence and ties to the White House, emerges from the shadows.

The CDC tries to identify the contagion and treat those infected as the biological threat intensifies; Simon asks Sophia to betray Thomas.

Sean encounters a mysterious conspiracy theorist while looking for answers in Leila's home; Simon's allegiances are tested.

President Martinez orders Director of National Intelligence, Blake Sterling, to root out the mole from their staff, which causes Sterling to question his judgment of people close to him. Sophia reasserts her power over Thomas and the other detainees, and she prepares them for the next leg of their mission. Elsewhere, with the aid of Madeline, Sean continues his hunt for answers, all the while trying to stay one step ahead of the covert agents who trail him.

President Martinez, furious about recent security failures, demands answers from Director of National Intelligence, Blake Sterling. When he doesn't receive the progress that he desires, Martinez decides to personally interrogate Michael Buchanan about his involvement in the assassination attempt. While Michael holds to his claim that he doesn't know who is involved, he inadvertently reveals incriminating evidence about someone deep inside the President's staff. Meanwhile, Dempsey dispatches Vicky on a new clandestine mission. And, elsewhere, Sean and Leila scramble to stay ahead of the covert ops that are trying to silence them and what they know.

President Martinez reacts to the knowledge of who betrayed him within his administration. Meanwhile, after revealing her plan for the Sleepers' future, Sophia learns of dissension among her people. She sets a trap for the perpetrators and acts decisively to quell any future mutiny. Elsewhere, Sean and Leila try to unravel the mystery of Samantha's kidnapping, while evading Dempsey's nefarious clutches.

Sophia's suspicions are confirmed when Thomas reveals a shocking new plan. Leila and Sean battle mercenaries while searching for Samantha.

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 lead on Samantha's location.

Meanwhile, newly appointed Alaskan Senator Catherine Lewis threatens to divulge information about the Mt. Inostranka detention facility on an episode of "HARDBALL with Chris Matthews." Elsewhere, Sean and Leila get a fresh lead on the whereabouts of Samantha, but it leads them to a dramatic turn in their lives. James Dempsey foresees that he and Sean will once again cross paths.