Donnie and Moretti are caught in the crossfire when a sniper shoots up the lobby of the Federal Building. When Pierce determines that the shooter is afraid of Extreme Low Frequency radio waves, he and Moretti take a trip to the Quiet Zone in Virginia, where they think the shooter is hiding out. Meanwhile, an alluring woman named Shelby Buchanan courts Donnie to run for political office.

After Dr. Daniel Pierce suffers a traumatic injury, his father, James, and his friend Paul Haley have to make a difficult choice on whether to allow Pierce to undergo a high-risk surgery. Meanwhile, Pierce works to solve a different kind of murder case that has him questioning everything he sees and hears.