The men are working on tracking down a known terrorist before he can launch an attack. At home, the women must face their own danger when a stranger approaches one of the children.

The team is assigned to stop of shipment of smuggled diamonds and Bob is conflicted when he sees one of the men helping themselves to the diamonds. On the home front, Molly and Kim are raising money to help the men and women serving in Iraq. Tiffy debates the war with protesters from a local school.

The team participates in a unique competition known as the CT Games that puts them up against other Special Forces units from around the world. Things take a bad turn when one of the teams appears to be taking things too far to win. Kim must travel to Utah to save her job and finds herself meeting an ex-lover. She spends some time getting reacquainted with him.

The Unit is back together and ready to take on their next assignment when a bomb filled with a nerve agent stolen from a nearby base is discovered to be on its way to their home.

On the home front, Jonas and Molly make plans to spend time together, Mack is ordered to move out of his home, and Kim proposes a new show for the station but ends up handling a crisis.

A Russian scientist and an Britsh MI5 agent are suspected of collusion. Jonas is sent to London to team up with the agent. However, things get complicated as Jonas had been engaged to the agent's wife earlier.