On the planet Mars, there existed a race of anthropomorphic mice who enjoyed Motorsports and had a very similar culture and society to that of human beings. At some point in time they were all but wiped out by the Plutarkians, an alien race of obese, foul-smelling, fish-like humanoids who exploit other planets for natural resources because they have wasted all of their own. Three survivors, Throttle, Modo and Vinnie, manage to find a spaceship and escape the Plutarkian takeover but they are soon shot down by a Plutarkian warship and end up crash-landing on Earth in the city of Chicago. There they meet a charming female mechanic named Charlene "Charley" Davidson and discover that the Plutarkians have come to Earth to steal its natural resources. The Biker Mice discover that Chicago's leading industrialist, Lawrence Limburger, is actually a Plutarkian who disguises himself as a human. Limburger enlists two henchmen, mad scientist Dr. Karbunkle and the idiotic Greasepit to help him steal Earth's natural resources and send them to Plutark. Thus, the Biker Mice become Limburger's chief foils, felling his business tower at the end of nearly every episode.