The series takes place about 70 years after the battle between Avatar Aang and the Fire Lord. Korra, who has already mastered the elements of water, earth, and fire, must learn the final element, air, with the help of Aang and Katara's son, Tenzin. Korra lives in Republic City, a place where people from all nations come together. The characters face challenges such as crime and a brewing rebellion against mages.