Aang is excited about going home for the first time in one hundred years, but he is shocked to find out that the temple is deserted. Aang tells Sokka and Katara about his childhood as they explore the temple, but they soon discover something that Aang never expected. Meanwhile, Zuko must make repairs to his ship and the only way he can do it is to dock his ship at his rival's naval base.

To contact the spirit of the previous Avatar, Aang must reach a temple in the Fire Nation before the sun sets on the following day. There he will learn what he must do to restore balance to the world. Zuko must defy his banishment to follow Aang.

While Aang, Katara and Sokka are traveling, Sokka gets a fever. Katara and Aang try to help Sokka, when Katara also catches the fever. It's up to Aang to go up on his own to save his two friends. But before he can get the medicine he is captured by the newly promoted Admiral Zhao and put in Zhao's fortress.

Aang returns from the spirit world to a big surprise. Meanwhile, Zhao and his forces continue to press deeper into the Northern Water Tribe. Iroh makes a powerful stand and Zuko struggles to keep his plan intact.