When an Afghan boy arrives at the warehouse looking for training as a jihadi, Darwyn introduces him to a more moderate brand of Islam in hopes of steering him away from terrorism.

The cell buys explosives from a white supremacist militia while Darwyn's new handler, Patrice Serxner, tries to prevent the LAPD from blowing his cover in a conflicting investigation.

Darwyn struggles to maintain his cover as he assumes command of a new Los Angeles sleeper cell and questions the experience and skill of his new FBI case agent. Farik's interrogators use new techniques to get him to talk.

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.