2. The Southern Lights

Complete story — includes the ending

Korra and company journey with Unalaq and his children Desna and Eska to the South Pole, where Korra is to attempt to return the long-absent Southern Lights, at Unalaq's urging. 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. At the South Pole, Korra succeeds in returning the southern lights by opening a blocked "spirit portal" one of two gateways which allows access to the spirit world and regulates the flow of spiritual energy between the two worlds. Returning from the pole, Korra's party discover that Northern Water Tribe have come to occupy the south at Unalaq's direction, to initiate a "reunification" of the two tribes. At the Southern Air Temple, Jinora is strongly drawn to the statues of the past avatars, particular that of her grandfather Aang and an unidentified carving of another ancient Avatar.