With hearts as big as their helmets, Throttle, Vinnie and Modo -- the Biker Mice from Mars -- are back and ready to take on all evildoers. The mice rumble with the no-good Catatonians, a cat-like race of creatures who seek the greatest prize in the universe -- the Regenerator, a device that can create anything upon request. The mice use it to make water, the cats want it to turn planets into giant sandboxes, and they'll scratch one another's eyes out to get it back from Ronaldo Rump, a Chicago real estate tycoon who has stolen it so he can transform Mexico into a humongous golf and hotel resort.