In the season 1 finale, Martinez and Peel are pitted against Jarvis and his ally; Leila struggles to survive; tremors are sent across the globe as the portal begins to open.

President Martinez returns to the White House, determined to punish those who conspired against him; Sophie struggles with guilt while forging ahead with her plan.

Sterling finds an unlikely ally in Simon; Jarvis authorizes an air strike without the chief of staff's approval; Sophia draws unwitting Leila into her plan; Sean and Vicky try to prevent many deaths.

While the White House deals with the unfolding tragedy, Sterling investigates his primary suspect; and Sophia manipulates the traitor. In other events, Leila and Michael try to rescue Simon; and Sean and Vicky set out to...

Peel and Sterling investigate a sudden illness in the White House; Michael helps Leila; Sean and Vicky try to prevent Sophia's weapon from being loaded onto a plane in Russia that's bound for the U.S.

Vice President Jarvis agrees to meet with an adversary; Sen. Lewis reports the results of the staff's blood tests; Sophia continues her search for the superweapon; Leila questions her place; Sean and Vicky find the perso...

The Sleepers mourn their losses after negotiations are derailed; Sterling tries to test Simon's loyalties; President Martinez asks Sen. Lewis (Virginia Madsen) to find any remaining moles in the White House.

Negotiations for the release of the Sleepers begin after Sophia triggers a national disaster; Sean and Vicky continue their mission.

Thomas shares the message he received with Sophia, Diane Geller and other Sleepers; Martinez confronts Jarvis about his betrayal; Sean blackmails Vicky into helping him; Dempsey hunts for experimental subjects.

President Martinez reasserts control after the attack in Alaska; Thomas drives Sophia and Martinez further apart; Michael leaves Leila with a friend and heads out to look for Thomas; the NSA works on decrypting a satelli...

A new Alaskan senator threatens to reveal information about the Mt. detention facility on "Hardball With Chris Matthews"; Sean and Leila discover new information about Samantha's whereabouts

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.