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 plunder other planets' 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, specifically in the scoreboard of Quigley Field. 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 investigate the crumbling ghetto of the windy city and soon discover that Chicago's leading industrialist, Lawrence Limburger, is actually a Plutarkian who disguises himself as a human, plotting to ransack Earth's resources to send to his own dying planet. 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. But the Biker Mice from Mars themselves as heroic vigilantes come to save the day, and stop Limburger from destroying Chicago, doing it to bring Plutark to justice as payback for the loss and powerful destruction of their home, and in the process defend the Earth from the same fate. The most frequent sign of victory is destroying Limburger's big tower, forcing him to constantly spend money to rebuild it.