Aang and friends arrive in the Earth Kingdom to begin his training, but a local general convinces Aang that all he needs to do is learn to control his Avatar state. Azula arrives to escort her brother and uncle back to the Fire Nation.

On their way to Omashu, Team Avatar is forced to travel underground to avoid Fire Nation attacks. Iroh and Zuko adjust to life as fugitives.

Finding the city of Aang's old friend, King Bumi, captured by the Fire Nation, the heroes hatch a plan to rescue Aang's earthbending teacher. Azula gathers two old friends to help her hunt the Avatar.

Aang hears a swamp calling to him. In the swamp, Aang and the gang find out that this is not any natural swamp.

Sokka and Katara have to solve a centuries-old crime when Aang is imprisoned for a murder allegedly committed by one of his past incarnations.

While looking for an Earthbending teacher, Aang, and his friends discover a young blind girl with secrets of her own.

As Zuko tries to make it by in exile without his uncle, he remembers how his father became Firelord and what happened to his mother.

Aang and friends are chased by a mysterious machine. Katara and Toph get into a heated argument. Aang realizes the reason why they are being followed by the crown princess and her friends is because of Appa's shedding.

Aang begins to learn earthbending from Toph; Uncle Iroh resumes teaching Zuko firebending to better prepare him for facing Azula, and reveals a new technique he learned from watching waterbenders.

When he learns that there is a lost Library with all the knowledge in the world, Sokka convinces the others to seek it out in hopes of finding a weakness of the Fire Nation.

Lost in the desert without Appa, Team Avatar must find a way out. Iroh and Zuko make contact with a secret organization.

After getting tickets for the ferry headed to Ba Sing Se, the gang meets an old friend. They skip the ride to help refugees get to Ba Sing Se. They must lead the refugees through the Serpent's Pass, a dangerous mountain-side path.

After arriving at the great wall of Ba Sing Se, Aang and the gang discover that the Fire Nation has constructed a drilling machine to penetrate the wall. Zuko and Iroh are having trouble hiding the fact that they are both Firebenders.

After getting a house to stay in, Aang and company are given a city tour. As they try to get in to tell the Earth King the news, they find that nothing is what it seems. Jet is in the city, too, and has suspicions about Iroh and Zuko.

A series of short stories covering some of the time spent by Katara, Toph, Iroh, Sokka, Aang, Zuko and Momo as they live in Ba Sing Se.

In this special episode, we go back in time to the moment Appa was stolen, will find out where he has gone and who he has met along the way and more importantly where he is now!

The Avatar gang encounters Jet in Ba Sing Se and he helps them to discover the location of Appa. But they will end up discovering something else, a secret of the city.

The kids battle Long Feng and the Dai Li when they attempt to show the Earth King the vast conspiracy taking place in his city. Zuko becomes seriously ill and has feverish dreams as he faces a spiritual crisis.

Aang receives guidance from Guru Pathik at the Eastern Air Temple; Sokka is reunited with his long-lost father; Princess Azula has something diabolical in store for her enemies; Uncle and Zuko run their own tea shop.

The heroes work together to stop Azula's destructive plans; Zuko finds companionship in an unlikely source and learns the time has come to make an imperative choice about his future.