The team scrambles against the Russians over a stranded submarine that houses U.S. secrets. Elsewhere, President Payton appoints a formidable new CIA director.

Charlie has flashbacks of Midnight City, where she first met Nick. In other developments, Charlie springs into action when militants kidnap 21 Nigerian girls, and President Payton has trade talks with the Chinese president.

Charlie and Nick receive a threatening text message each that then sees Nick attempting to find the source once and for all.

With part of the convoy attack report having been leaked, President Payton has a lot of questions for Nick Vera to answer. Unfortunately though he seems to be missing in action.

Charlie and Maureen accompany President Payton to Qatar on a diplomatic trip. What begins as a standard mission of diplomacy becomes a disaster when a Qatar national infiltrates the American embassy claiming to be CIA.

Numerous photos of national landmarks featuring an Arabic symbol surface. Meanwhile, Charlie is in Yemen to make contact with her asset, Nick's masked captor leads him to his next mission, Lucas oversees an interrogation at Langley, and President Payton must make a difficult decision.

When The Revolutionary Forces of Colombia kidnap Jack Dawkins from a Panamanian prison and want a ransom for his safe return, the team has to find his location and rescue him before time runs out.

Charlie and the team attempt to prove that sorority girl Stacy Dover is an active member of Ar Rissalah's American terrorist cell.

As they attempt to find some missing bombs, Charlie needs to turn to a former adversary for help.

Charlie and Lucas attempt to assist a FBI search for a terrorist who has escaped custody in West Virginia.

Sacrifices may need to be made when Nick at last has the most-wanted terrorist in his sights, and Charlie is at odds with President Payton on how to proceed. Meanwhile, Sen. Burke releases secret intelligence that jeopardizes the entire mission, and Charlie's past with Nick comes to the fore.

Charlie quits the CIA to track down Omar Fatah; the seventh floor team vows to help Charlie.