Korra and Team Avatar embark on a new journey deep into the mythology of the mystical Spirit World, encountering creatures like nothing they've seen before and discovering the truth about the very first Avatar! With a battle for the fate of the world between the light and dark spirits Raava and Vaatu fast approaching, 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.

Title from web page. Bonus features: Commentary: audio commentary; Additional scenes: additional scenes.