Rye's defeated the sorcerer Olt, freed the island of Dorne, and rescued one of his brothers, but when he returns to the city of Weld with his three companions, he finds that very little has changed--the skimmer monsters still attack at night and the Warden is behaving very strangely.

Through an heirloom music box, Leo, a serious, responsible boy, and his badly-behaved cousin Mimi enter the magical world of Rondo to rescue Mimi's dog from a sorceress, who wishes to exchange him for the key that allows free travel between worlds.