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 seeks Tenzin's help to enter the Spirit World for the first time.

Korra enters the Spirit World and struggles with the Avatar's relationship with the spirits.

Korra and company attempt to close the spirit portals before Harmonic Convergence.

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 battles Zaheer, while Bolin and Mako duel Ghazan and Ming-Hua. The captive members of the Air Nation escape and band together to help Korra.

In a clip show episode, Mako, Korra, and Bolin recollect their past. Mako tells Wu about his romantic entanglements and eventual breakup with Asami and Korra. Korra talks to Asami about her confrontations with Amon, Unalaq, Vaatu, and Zaheer. Varrick presents Bolin's life to the Earth Empire refugees in the style of an action film in which Bolin defeats all of Korra's previous enemies.