Sherlock and Watson investigate a child abduction case involving a serial killer known as "The Balloon Man."
Tony's son AJ is suicidal over his break-up with Blanca, and Christopher falls of the wagon with catastrophic consequences.
While the Soprano and Lupertazzi crime families clash over asbestos removal, Paulie struggles to deal with a devastating personal loss.
Tony attempts to repair the rift between New Jersey and New York. Elsewhere, AJ's depression continues, and an associate crosses the line with Meadow.
A crucial agent crumbles under emotional distress and threatens to topple a valuable network of KGB informants. Professionally, Philip and Elizabeth are tasked with infiltrating the FBI's new communications encryption system.