When does The Legend of Korra return?

The Legend of Korra is a sequel to their previous series Avatar: The Last Airbender. The series ran for 52 episodes, separated into four seasons, from April 14, 2012, to December 19, 2014. The main characters are voiced by Janet Varney, Seychelle Gabriel, David Faustino, P. J. Byrne, J. K. Simmons and Mindy Sterling. Only one person, the "Avatar", can bend all four elements and is responsible for maintaining balance in the world.