After learning the latest person of interest (Alan Dale) has connections to Cold War Soviet espionage circles, Reese and Finch learn how covert operations used to be handled.
After a financial scam destroys the reputation of lawyer Maia Rindell, while wiping out her mentor and godmother, Diane Lockhart's, savings; Maia and Diane join one of Chicago's preeminent law firms.
Having lost a number of essential personnel to Nazir's terrorist plot against the U.S., the CIA issue polygraph tests on everyone who had contact with them. This includes Brody, which Carrie hopes will reveal the truth about him.
An explosion injures a pregnant guard and exposes a scientist's controversial research.
Picard risks war when he refuses to return a human boy to the alien father who raised him, and may have abused him.