The Unit is sent to Los Angeles to protect Mexico's drug minister who has been threatened with assassination and soon his wife and sons are kidnapped. At the base, a former Unit wife makes a return appearance in the hopes of luring the Unit members away. Tiffy is upset when Ryan orders Mack to take time off.

The team is sent into Iran to set up a system that can detect Weapons of Mass Destruction. The mission goes off kilter when civilians become involved.On the home front, Tiffy runs into a dilemma while doing her community service. Molly and Kim are helping Jeremy and are confused by Crystal's behaviors. Mack finds himself in trouble.

The Unit faces its greatest threat when they are investigated by the Government for their actions. Each man must make difficult choices, which may put their entire team in jeopardy.

Jonas is still in hiding, Mack and Hector are still imprisoned, Charles is on the run, Bob is in Mexico, working for the CIA and Colonel Ryan is again called to answer question before a Congressional hearing.