America copes with tragedy while Chandler further investigates the possible virus mutation.

Chandler gets a lead that could help answer threatening questions. Kara does some digging in the White House.

Chandler finds himself making a difficult decision when an order comes in from the White House.

Chandler faces his powerful enemy in a final showdown. Kara joins someone that can help with her mission.

Chandler returns to America to find out what has really been happening.

The fight for America comes to an end; Chandler faces a challenge that could change his life forever.