The key to Rondo

Description:

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.

subjects: Magic,  Witches,  Adventure and adventurers,  Cousins,  Music box,  Space and time,  Fiction