Key the Steampunk Vampire Girl has been thrown into the Dungeon of Despair and lost in the past through the Tower Tomb of Time, and now she lives in a magical mansion that floats beneath a hot air balloon. On the outside it looks ordinary while the inside has numerous bewitched hallways like a maze and countless enchanted doors that can lead anywhere in the world! But when two villains take over the Floating Mansion, Key works desperately to get it back with the aid of old friends like Miss Broomble the Witch and Mr. Fuddlebee the Ghost and her new friend, ARTH-R the Robot. However, the villains have a secret weapon: They know the location of Key's missing parents! In the end she might win back not only her house but also her home.