Darwyn wants to start a new life with his family, Gayle and Marcus, but instead he finds himself drawn into another Sleeper Cell based in LA.
Darwyn has trouble with his new position as leader of the cell. He also conflicts with his new FBI Case Agent, Warren Russell. Darwyn worries that Warren's lack of field experience may lead to problems.
Darwyn finds out that the attack his cell is planning will involve nuclear material.
In Najran, Saudi Arabia, Farik, now free uses his resources to help further the nuclear plot against LA.
Darwyn believes that the nuclear material will arrive at the Port of LA, so he tells the FBI to prepare for picking up the material and taking down the cell.
The new cell leader is making things more difficult for Darwyn. He struggles working for the new leader and tries to gain information even though the new leader is cutting him out of the planning of the cell's upcoming attack.
On the 4th of July, the cell gets ready to launch two simultaneous dirty bomb attacks on LA. Meanwhile, Darwyn and the FBI are trying to stop it. Mina is successful with the suicide bomb attack.
Darwyn feels guilty and blames himself for Gayle's death and for Mina's successful suicide bombing attack. So he goes to Yemen on a suicide mission to find Farik.