The vast steam continent contains seven intelligent species and six major civilizations. After a mining accident killed her adopted father, the human girl Arno and her companion Bu found an ancient artifact in the abyss. As she embarks on a journey for the truth, covetous eyes will be watching her: The bird country filled with hidden dangers, the cat country sealed by ice, the rabbit country shook by political crisis, and the lion country troubled by drought... Where will be the end of Arno's journey?