In order to stop a terrorist cell carrying out a chemical bombing at an unknown location in the city, the team joins forces with an old school code breaker who is suffering from agoraphobia. Together they decipher a seemingly unbreakable cipher. Meanwhile, Colin wrestles with Toni's return to the field, and Bill braces for Katie's response to his recent admission.
CIA case officer Colin Glass is a bit of a loose cannon with no regard for the rules, and FBI special agent Bill Goodman is strictly by-the-book. When this odd couple are assigned to work out of CIA's New York Station, they must learn to work together to investigate cases and criminals posing threats on U.S. soil, finding that their differences may actually be their strength.