Aang and his friends continue to search for Appa and, unbeknown to them, they aren't the only ones looking for him. During their search, the kid's meet up with Jet, whom they are understandably reluctant to trust. The kids soon realize that the Dai Li are doing their best to thwart the kids efforts to find Appa. Meanwhile, Uncle Iroh is offered his own tea shop in the upper ring, and Zuko discovers the Avatar is in the city.

With the plans to invade the Fire Nation finally underway, everyone begins their own respective missions. Aang receives guidance from Guru Pathik at the Eastern Air Temple, Sokka is reunited with his father, Katara begins to help the Council of Five plan the invasion, and Zuko and Iroh begin to settle into the new lives of owning a tea shop. However, things are not what they seem. Toph has been captured and is being brought back to her parents, and Azula has infiltrated the city and is planning on finally conquering Ba Sing Se for the Fire Nation. Will Azula succeed? Will Toph escape, and will Aang finally master the Avatar State?