On the other side of the world, to the west of the Fire Nation, to the east of the Earth Kingdom, lies the Great Sea. No one dares venture into the Great Sea: only the desperate—exiles from the world of humans and people with no other place to go. No one comes back from the Great Sea.
Legends say that before the time of men, fearsome creatures roamed the world: sea creatures the size of small islands, monsters the size of a city, and flying beasts that could blot out the Sun. But at the dawn at the age of men, these creatures retreated to the Spirit World or the Great Sea.
But a new age has arrived, and these creatures of legend and myth have started to reappear in the world of humans, destroying the works of man, ravaging the Fire Nation in the west and the Earth Kingdom of the east. The world is out of balance. One hundred years of war have scorched the land and sea. In the new peace, forests continue to be destroyed and the land scarred in order to rebuild the cities of men. Where are the guardians of the peace between men and nature? The Avatar has returned for the humans but what about nature? The great air bison and dragons have disappeared.
The Avatar has restored peace among the people of the four nations. Can he bring peace between the elementals of the spirit world and the humans?