When the elusive Moeteshio invade Republic City and attempt to kill the Avatar, the world blames the Fire Nation for the attack. As the others try to maintain peace in both the human and spirit worlds, Sokka and Ty Lee set out to find and stop the mysterious group.

Though successful, the battle for Trost District suffered casualties. After losing companions and harming his dearest friend, Eren questions his humanity and the risks inherent in his Titan powers.

After a devastating incident shatters Tipa's caravan, a new caravan must take its place. Eight young members of the four races must unite to protect their home from the lethal miasma. Burdened by their village's tragic history, Tipa's caravan must set out and face a dark world brimming with deadly monsters and hostile racism.

Although the Yuke Crystal has been restored, miasma and monsters continue to enter the world. When Layle is sent to recover the lost Selkie Crystal, he discovers a dark force which intends to destroy the four tribal crystals and once again cover the world in miasma.