The president and his chief of staff (Roger Bart) order the intelligence community to decrypt Thomas' satellite message and also figure out to whom it was sent; a surprise attack by Thomas is handled by Blake in a heroic...

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

Sophia sets a trap after discovering dissension among her people; Leila and Sean investigate Samantha's kidnapping and try to evade Dempsey (Hal Holbrook).

President Martinez interrogates Michael about his involvement in the assassination attempt; Vicky is sent on a new secret mission.

Sterling becomes suspicious of the people close to him; Sophia prepares Thomas and the rest of the detainees for the next part of their mission; Madeline (Paula Malcomson) helps Sean look for answers.

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

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

The White House must deal with a mysterious biological threat; Carter and Vicky keep their hostages alive while waiting for more instructions; FBI Agent Collier discovers Vicky's secret life.

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

Following the plane incident, the president's men scramble to figure out what happened; Sterling has Sophia taken into custody; and the conspiracy's web snares an FBI agent Collier (Heather McComb) and a mercenary Carter...

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