The Biker Mice get their hands on Rump's Regenerator in time to be accidentally transported to Saturn, thanks to Hairball's clumsy control of a transporter machine. With no way off the ringed planet, the mice turn to a race of local hip cats. However, they discover that these wave-riding kitties are descendants of the Catatonians (sworn enemies of the Mice). Will the slick, surfing cats of Saturn turn out to be friend or foe?