ook Three: Change (易) is the title of the third and penultimate book of The Legend of Korra, which will run for a total of thirteen episodes. Set two weeks after the end of Book Two: Spirits, the nomenclature refers to the changes induced by the energy shift of the planet due to Harmonic Convergence and Korra's battle with the Dark Avatar.
As of May 8, 2014, the animation for Book Three has been completed by Studio Mir. Production work for Book Three was officially completed on June 3, 2014. The book debuted with the first three episodes airing on June 27, 2014. On July 24, it was announced that following the airing of "The Terror Within", the remaining five episodes of the book would be moved to online releases, including Nickelodeon's website.Overview from themoviedb.org