A patriotic, xenophobic terrorist calling himself the Ameri Bomber destroys a federal building in Denver and booby traps his cabin. Eventually, the identity of the bomber is revealed to be a relative of Nate's who happens to have Nate's access codes, so both are implicated in the bombings. After backstepping, Frank and Nate must work together to prevent the Ameri Bomber from continuing his campaign of fear, save Nate's career, and save Nate's brother's life...