Avatar Korra fights to keep Republic City safe from the evil forces of both the physical and spiritual worlds. Book Two: Spirits is the second season of the animated TV series The Legend of Korra by Michael Dante DiMartino and Bryan Konietzko. It consisted of fourteen episodes ("chapters"). A sequel to The Legend of Korra: Book 1, it focuses more on spiritual concepts and themes. Ordered in early 2011, Book Two: Spirits began airing on Nickelodeon in the U.S. on September 13, 2013.