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.

Aang and friends visit a village being terrorized by an angry spirit. Iroh is captured by Earth Kingdom soldiers.

Aang, Katara and Sokka have run out of money. Katara suggests Sokka get a job, and coincidentally, they meet a fisherman who is looking for someone to help him out with his fishing. But when the fisherman recognizes Aang as the Avatar, he blames Aang's absence for all of the troubles of the last 100 years, and Aang runs away on his glider. Katara follows on Appa, and when she finds him, Aang begins to reveal his life before he was frozen in the iceberg. Meanwhile, Zuko and Lieutenant Jee get into a fight, but Iroh breaks it up. Soon thereafter, the Lieutenant and the rest of the crew gain a newfound respect for their leader after learning of his past.

Aang and his friends go to a Fire Nation town so that Aang can witness some firebending, but their plan soon goes awry when it’s discovered that he is the Avatar. Fortunately, he's rescued by an individual who serves a firebending master named Jeong Jeong who has abandoned the Fire Nation, so Aang decides to use this time to attempt to learn firebending. The firebending master, however, seems reluctant to teach Aang.

On their way to Omashu, Aang, Katara, and Sokka meet a group of nomads who show them a shortcut through the "Cave of Two Lovers". But when the group becomes trapped in the cave, it's up to Aang and Katara to save the group by trusting in love, possibly questioning their relationship. Meanwhile, Iroh gets a lethal rash so Zuko and Iroh head to a small Earth Kingdom town for help, hoping their real identities will not be discovered.

Aang and the gang discover an Earth town that celebrates something called "Avatar Day." But when they get there and learn the festival is of "anti-Avatar" sentiment and Aang is put on trial for a crime a past incarnation allegedly committed. Looking to clear the Avatar's good name, Katara and Sokka venture back to a familiar place to gather evidence and discover the truth.

Zuko travels by himself to an Earth Kingdom town were he meets a local boy. The two almost become friends, while Zuko suffers from flashbacks of his past.

Aang searches for Appa while Katara struggles to keep everyone together to survive in the vast desert. Meanwhile, Iroh and Zuko seek help from an ancient secret society.

Having finally made it into Ba Sing Se, the kids are given a house in the upper ring. The kids are anxious to tell the Earth King their plan but there are complications. Meanwhile, still convinced that Iroh and Zuko may be Fire Nation, Jet decides to take matters into his own hands and do whatever it takes to get the refugees to reveal their true nature.

Aang and his friends continue to search for Appa and, unbeknownst to them, they aren't the only ones looking for him. During their search, the kids 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, Iroh is offered his own tea shop in the upper ring, and Zuko discovers the avatar is in the city.