Although they fail to track them down, Korra learns that Kuvira is harvesting vines in the Foggy Swamp. After permanently fusing with Wan, she was transformed into the divine Avatar Spirit. In order to save her, Korra and Mako enter the Spirit Wilds, though finding her path to the Spirit World blocked by Zaheer, Korra decides to confront him. To protect him from further kidnapping attempts, Wu is left at Asami's residence to stay with Mako's extended family. Upon exiting, Kuvira tells her army to step down as she is taken away in handcuffs by Lin and Suyin.
Opal admits her reluctance to leave Zaofu due to her obligations to her family while Bolin deals with his fear of learning how to bend metal. After using her last element to expose Amon's true identity, the Equalist leader flees the city with Tarrlok, who uses an to blow up their speedboat. The premiere episode was shown in full at The Legend of Korra panel at on 19 July 2013, together with the release of a trailer video for Book Two. Surprisingly, Jinora has a difficult time locating Korra's spiritual energy, and the lack of progress causes tensions to run high between the siblings. While meditating in the Tree of Time, she manages to tap into the energy of the universe and astrally projects herself, instigating a fight with Unalaq at Republic City. After a brief break, the fourth and final book, titled , premiered on October 3, 2014, and also ran for thirteen episodes.
Korra fails to persuade President Raiko to send troops in support of the Southern rebellion. Korra, Jinora, and Opal walk out to stop Kuvira, who has her entire army ready to invade the metal city. Wan and Raava fail to stop a bloody war initiated between the humans and spirits by Vaatu. At Air Temple Island, Korra tells Asami how she was doubting herself and her position as bringer of balance. He said that Studio Mir initially chose to focus on animating the less challenging rather than the second season of The Legend of Korra because of the exhaustion brought about by their work on the first season. Meanwhile, Varrick starts to get troubled by his conscience and refuses to further develop the spirit vine technology.
Korra confronts Tarrlok late at night, resulting in Tarrlok's exposure as a bloodbender. The show returned on September 13, 2013, with the television debut of the first two episodes of. Amon baits her and succeeds in taking Korra's bending except for airbending, since she had not yet unlocked the fourth element. When Kuvira threatens to kill him, however, he continues his work to weaponize the spirit energy. Successfully evading arrest by the guards, they reach the shore and are given a lift in gratitude for their help. She and Opal leave to inform President Raiko about the situation, while Jinora continues her search. While Team Avatar reunites, Opal and Lin plan to leave the city to rescue their family in Zaofu by themselves.
In the city, Tenzin fights off a kidnapping attempt of the Equalists and ends up the sole council member left, prompting him to request help from the United Forces. Sometime afterward, Varrick and Zhu Li get married at Air Temple Island with Bolin presiding. Korra turns to Varrick, who agrees to give her his personal battleship. While Korra has an audience with the , who demands her to go collect tax money from a small village as a condition for the Queen's help to track down airbenders in the city, the others notice that Kai has gone missing, prompting Mako and Bolin to go look for him. In Republic City, Mako continues his investigation of Varrick. After seeing Kuvira show how powerful her weapon can be, Raiko surrenders. Jinora is anointed as an airbending master by Tenzin, who also proclaims that the Air Nation will return to its nomadic roots and serve as the world's ambassadors for peace and balance.
Once there, she is shocked to find the bustling metropolis rife with corruption, criminal , and a vocal. Meanwhile, in the Spirit World, Bumi, Kya, and Tenzin manage to track down and save Jinora's spirit from the. With a conflict brewing, Tenzin tasks his three eldest children to search for Korra and bring her back to Republic City. Worried, Korra and Mako search for him and they learn of an upcoming Equalist. Elsewhere, Zaheer and his group determine Korra's whereabouts shortly after escaping Republic City, deducing that she is under the Metal Clan's protection in Zaofu. However, she eventually ends up being killed by Zaheer, who subsequently has Ghazan take down the city's inner walls.
There, she befriends the brothers and , who compete in matches on their team, the. After both earlier releases, released a season pass and the first two episodes on April 3, 2012. Meanwhile, Korra finds herself in a dark forest, where she reverts to her four-year-old self and encounters 's spirit. Kuvira announces to Zaofu what Suyin has done and tells its leaders to step forward and surrender. As she tries to reconcile with her mother, Senna, and Tonraq, Unalaq appears to arrest them for conspiring to assassinate him. Meanwhile, in Ba Sing Se, Mako and Bolin are imprisoned while the Red Lotus strikes a deal with Earth Queen Hou-Ting.
Sitting with Asami, Korra apologizes for her long absence while Asami says that she is just happy to see her alive and cares deeply for Korra. Mako investigates further and discovers the true culprit when he notices Varrick's mover technicians use the same type of detonators as he found during the. There, Korra is able to locate the airbenders, who had been pulled into the swamp by vines. With Varrick's help, she and Team Avatar free all the rebels. When Korra learns that her father was once banished from the Northern Water Tribe for causing a spirit rampage, and that he and Tenzin were responsible for her seclusion in her youth, she insists on Tonraq returning home, and tensions begin to grow between herself and Tenzin. Having defeated Korra, the Dark Avatar grows to enormous proportions and makes his way toward Republic City.