General Stoker's exposure to tetra-hydrocarbons has worsened his condition, turning him into the mad "Stoker Rat". He is loose in New York City, where Rump has captured him ito force Stoker to build another Regenerator for Rump so he can become richer. Will Stoker turn traitor? Can the Biker Mice rescue him from the clutches of Ronaldo Rump and get him back to work in the effort to save Mars?