The Ultimatum
In the sequel series "The Legend of Korra", Iroh is revealed to have used a form of astral projection at the time of his death to become a resident of the Spirit World. In the episode "A New Spiritual Age", Iroh comes to the aid of Aang's successor as Avatar, Korra, who is trapped unprepared deep in the Spirit World. In the episode "Darkness Falls", having known them in life, Iroh encounters Aang's children Tenzin, Kya, and Bumi when they enter the Spirit World and provides them with hints as to the location of the spirit of Tenzin's daughter Jinora. Korra again encounters Iroh in "The Ultimatum," when she enters the Spirit World in search of the anarchist terrorist Zaheer. Korra explains to Iroh that she is confused and doesn't know how to deal with the threat Zaheer poses to both the newly reformed Air Nation and the world. Iroh suggests that Korra seek Zuko's counsel, as Aang once did.