Darwyn risks blowing his cover to stop one of his cell's operative from taking revenge against a progressive Islamic televangelist; Farik escapes from prison in Saudi Arabia and finds an al-Qaeda safe house.

The future of Darwyn's cell is altered when he urges the FBI to intercept a shipment of nuclear material arriving at the Port of Los Angeles - sent by none other than Farik; Ilija faces his past when he arrives home in Sarajevo.

The cell's new leader, Karrar, pushes Darwyn aside as plans progress for the nuclear attack on Los Angeles; Farik teaches a lesson about the terrorist way of doing business to an American philanthropist at a school in Yemen.

The FBI and Darwyn move to intercept the cell's plans to detonate a pair of nuclear dirty bombs in Los Angeles on the Fourth of July, but their victory is overshadowed by a pair of tragedies for Darwyn.

Darwyn blames himself for the tragedies that occurred on the Fourth of July and embarks on a suicide mission to Yemen, where he plans to find and confront Farik using his former cell leader's wife as bait.