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 (Laura Innes) during interrogation. Meanwhile, Vicky (Taylor Cole) and Carter (guest star D.B. Sweeney) keep their hostage captive while they await further instructions. FBI Agent Collier (guest star Heather McComb), on her search for Leila (Sarah Roemer), stumbles upon Vicky's secret life. Elsewhere, a powerful businessman, Dempsey (guest star Hal Holbrook) with classified intelligence and ties to the White House, emerges from the shadows. Jason Ritter, Blair Underwood, Željko Ivanek, Clifton Collins, Jr., Ian Anthony Dale, Scott Patterson, Lisa Vidal, and Bill Smitrovich. Directed by: John Badham.

The biological threat intensifies. The CDC rushes to identify the contagion and treat the infected people, while the White House and Director of National Intelligence (Zeljko Ivanek) face a difficult dilemma in their negotiation with Thomas (Clifton Collins, Jr.). Meanwhile, Simon (Ian Anthony Dale) appeals to Sophia (Laura Innes) to turn on Thomas. Elsewhere, FBI Agent Collier (guest star Heather McComb) closes in on Vicky (Taylor Cole) and Carter (guest star D.B. Sweeney), but appearances are not always what they seem. Jason Ritter, Sarah Roemer, Blair Underwood, Scott Patterson, Lisa Vidal, and Bill Smitrovich. Directed by: Milan Cheylov.

President Martinez (Blair Underwood) and the Director of National Intelligence, Blake Sterling (Zeljko Ivanek), fulfill their agreement with Thomas (Clifton Collins, Jr.), but after their plan goes awry, they suspect that there is a possible mole in their midst. Elsewhere, Sean Walker (Jason Ritter) digs for answers at Leila's home, where he encounters Madeline (guest star Paula Malcomson), a mysterious conspiracy theorist. Meanwhile, Simon's (Ian Anthony Dale) past is illuminated, and his allegiances are tested. Sarah Roemer, Laura Innes, Scott Patterson, Lisa Vidal and Bill Smitrovich also star. Directed by: Jonas Pate.