Plagued with nightmares featuring the devastating power of his Avatar State, Aang and the gang meet an Earth Kingdom general who has big plans for defeating the Fire Nation. Meanwhile Prince Zuko and Uncle Iroh, having survived the failed attack on the North Water Tribe, have a surprise visit from the Prince's sister with seemingly good news.

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 and 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.

Despite finding out that Omashu has been captured by the Fire Nation, Aang insists on trying to find King Bumi within Omashu's borders, even with the dangers that will await him and his friends if his real identity is discovered. Meanwhile Azula goes in search of old friends to help her with her mission. Can Aang locate his friend Bumi or will Azula succeed in capturing the avatar?

A mysterious tornado pulls the kids into a supernatural swamp where Katara, Sokka, and Aang have mysterious visions. Meanwhile, Momo and Appa are chased by rogue swamp dwellers.What mysterious forces hide in this swamp, and will Aang get there in time to save Momo and Appa?

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. Can Aang redeem himself in the eyes of the people of the Earth town?

In search for an earthbending teacher for Aang, the kids go to an underground earthbending tournament called Earth Rumble 6. There they meet Toph (aka the Blind Bandit), a blind, but powerful earthbending girl. After seeing her unique style of earthbending, Aang wants Toph to become his teacher, but they find out Toph has hardships of her own. Will Aang manage to convince Toph, or will he be left without an earthbending teacher?

Following a fight with Uncle Iroh, Zuko travels by himself to an Earth Kingdom town were he meets a local boy. The two almost become friends. Meanwhile Zuko suffers from flashbacks of his past. Can Zuko save his friends and remember who he is?

When a mysterious vehicle follows Aang's group they try to escape but it appears every time they try to rest. They confront it but Azula emerges and attacks and they are forced to run again. The tension grows among them and Toph leaves the group but finds help from an unlikely source.

Meanwhile, Aang tries to draw their pursuers away and finally faces off against Azula. Zuko also arrives determined to claim his prize...

Toph's instructing abilities come into question when Aang cannot seem to overcome a block that keeps him from earthbending. Sokka gets himself in a jam while befriending what was, moments before, his next meal, and Iroh and Zuko begin training utilizing new philosophies and methods that originate from the other elements. Can Aang learn earthbending or did the world get an avatar who cannot master the four elements?

When Aang and his friends meet a professor who knows of a library that contains information about the world, Sokka decides to go there to try and find some information to use against the Fire Nation. The library is guarded by the knowledge spirit, Wan Shi Tong, who doesn't welcome humans into his library, because he believes they only seek information for evil purposes. When Wan Shi Tong discovers Sokka wasn't being truthful with him, he begins to sink the library, bringing the kids down with it. Will everyone be able to escape the library in time? And who are the strange benders who are trying to kidnap Appa?

Aang searches for Appa, while Katara struggles to keep everyone together so they can survive in the vast desert while Sokka supposedly gets "high" of Cactus juice in the desert. Meanwhile, Iroh and Zuko seek help from an ancient secret society. Will Aang find his furry friend or did the sandbenders cause a catastrophe?

When Aang and the gang meet up with a group of refugees, they tell the gang where they can get on a ferry to Ba Sing Se. But after a series of events they have to take a deadly route called the serpent's pass with the help of an old friend, Suki. Meanwhile Zuko and Iroh meet up with a boy named Jet and his freedom fighters. Can Aang and the gang trust to hope to get them out of the treacherous Serpent's Pass?

Having made it to the outer wall of Ba Sing Se, the kids confront a Fire Nation army that is driving a massive Fire Nation drill, which poses an imminent threat to the last Earth Kingdom stronghold. Meanwhile Zuko and Iroh make crucial mistakes which begin to attract Jet's suspicions. Can Zuko and Iroh keep their cover? Will Aang manage to save Ba Sing Se from the Fire Nation?

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.

A series of short stories highlighting different characters and their individual adventures in the city. Tales of Katara and Toph, Iroh, Sokka, Aang, Zuko, and Momo.

We go back in time to the moment Appa was stolen to see all of the adventures the poor bison has had, including his adventures with some special friends. Can Appa find his way back to Aang, or will the gang miss an important friend?

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.

The kids break into the Earth King's palace to find that Long Feng has already prepared for them. The kids beg for the Earth King's trust, but it's not as easy as they expect. Meanwhile, Zuko is going through a horrible sickness.

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. Meanwhile, Katara and Toph run into some trouble in Ba Sing Se. What will all these things lead to, and is Aang ready for the future?

Everyone races against time to stop Azula's sinister plan. Zuko finds companionship in an unlikely source. Aang's destiny hangs in the balance and so does Zuko's, as Iroh tells him "it is time to choose." Can Zuko choose the right path during his crossroads of destiny or will the Fire Nation finally win?