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.