Millhouse is a faint-hearted, hairless guinea pig. A great lover of all things theatrical, most especially the work of William Shakespeare, Milly longs for the limelight and someone to love. However, after the death of his beloved owner, the great actor Sir Roderick Lord Kingswagger, Millhouse is abandoned to a neglected and dusty pet shop filled with other rodents -- some rude, some odd, some cute and some downright frightening. Finding himself a reviled outcast and a target of the nasty Pepper Brown ferret, Millhouse sets about trying to find a way back to the theater and a happy home, and in doing so experiences more drama than he could ever have imagined.