Former Marine Wade Stuart, an ATF special agent, finds himself working undercover in his home territory, Mississippi, infiltrating a militia unit with lofty goals. When Stuart uncovers a plot to assassinate the governor and take over the state as part of a people's revolution, Washington plans to send in the 2nd Marine Division to attack the militia. Stuart sees a bloodbath coming, begs for time to quash the plan, but the President sees this as an opportunity to set an example. Isolated and unsure of the decision out of Washington, Stuart must race to shut down the militia before the military arrives. Enemy Within rushes forward at breakneck speed, and only man can stop these domestic terrorists -- Wade Stuart!