The Unit must locate and diffuse three sets of dirty bombs headed for unknown locations across the United States.
While Jonas is tracking down a Russian terrorist cell, Molly is used as bait.
A random incident throws Jonas and Bob's carefully planned mission into chaos.
The Unit hunts down one of their own after Sam attacks Bridget.
When Jonas and Mack go undercover to find the terrorists who killed the Vice President, the mission's plans go awry and Bob must run interference.
Time is running out for the Unit when a broken helicopter gas tank and nearby guerillas impede their rescue mission of Jonas's old friend.
Without any communication to the outside world, the Unit and their families must survive when a deadly gas poisons anyone in their community who steps outside.
As Jonas coaches Betsy before her military-ordered media tour, the Unit initiates a new team member.
The President orders the unit to capture a Nazi war criminal from his hiding place and deliver him to The Hague. In Washington, Tom Ryan confronts his past when he is offered a promotion to General.
Jonas and a seriously wounded Mack take refuge in a monastery where he is ordered to steal the monks' most prized possession.
Jonas plays a game of high stakes baccarat to win back the services of a CIA spy who has gone over to the other side. His success is also key in getting court martial charges against team member Bridget Sullivan dismissed.
Jonas and the team make a Dept. of Defense official, whose bad judgment caused a mission to fail, go on an assignment with them where he will experience the realities of war first hand. Back home, Kim is secretly reunited with her children.
The team's efforts to raid an anthrax lab are thwarted by an official who thinks his high-tech intelligence is superior to their field logic. At home, Kim's life is in danger when her boss commits a murder and forces her to help get rid of the body.
Jonas and the team must go through enemy territory to bring a young bride to her groom in order to preserve a truce between two warring Afghanistan tribes. At home, Bob and Kim work together to expose a man who is linked to terrorists.
While Jonas and the team continue to try to rescue his daughter, Betsy Blane, from Syrian captors, Mack has the opportunity to carry out his revenge on Ryan for his affair with Tiffy.
When Betsy Blane is taken hostage, Jonas and his team go to Iraq and begin their plan to rescue her. On the home front, Mack works on making Ryan pay for having an affair with Tiffy.