Korra learns about the epic and mythic origins of the first Avatar.

Korra delves deeper into the Avatar's past and realizes what she must do in order to restore balance between the physical and spirit worlds.

Korra discovers a new twist in Unalaq's evil plan. Meanwhile, Tenzin realizes he must face his own demons in order to save his daughter.

Korra discovers a way she may be able to defeat the ultimate dark spirit and save the world.