 In this season of change, Bo and Luke leave Hazzard to pursue careers on the NASCAR circuit. Thinking no one named Duke is available to stop him, Boss unveils his secret weapon: the Mean Green Machine, a large tank that his henchmen plan to crash into banks to set up armed robberies. After Coy and Vance - arriving in town for what will turn out to be a temporary stay - have an all-too close encounter with the tank, they go to Boss and Rosco to demand answers, but Boss professes his ignorance of the situation. Also in this episode, Enos returns to the Hazzard County Sheriff s Department, temporarily bumping the police force to three officers.