McNulty and his staff must act quickly to keep a terrorist ally from slipping away. Meanwhile, someone from JT's past figures into his misson of sending his old unit into harm's way when a high-risk mission requires the best of the special-ops teams.

When Angie is put in a dangerous situation, she can only leave him one clue as to what has happened to her. JT must recall his old Special Ops missions in order to find the answer.

In Columbia, JT is heading an undercover operation to nail the drug lord who attacked Angie. Now he has to finish a job they started together years ago.

Back in the Pentagon, Sam finds evidence on the CIA director and has him indicted.

On Christmas Eve, JT works on a humanitarian aid mission for an Afghanistan village that helped Delta several years ago. He finds the village confronting bad weather and an advancing Taliban force. Also, Sonny helps JT's father who needs a favor.

JT undergoes a psychological evaluation in which he recounts a mission to Lebanon to save one of his men who was tortured by insurgents.