Two teenage siblings (Sokka and Katara) living in the South Pole discover a very strange boy (Aang), along with his pet flying bison Appa, in an iceberg. But can they trust him when he accidentally draws the war to their village's doorstep?
Katara and Sokka discover that Aang is the long-lost Avatar and must rescue him when a Firebending prince named Zuko kidnaps him.
Aang is excited about going home (the Southern Airtemple) 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, Prince 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.
The gang arrives at Kyoshi Island and are captured by some Kyoshi warriors. When Aang reveals that he is the avatar, news quickly spreads out and suddenly reaches to Prince Zuko who then goes to Kyoshi Island to capture him.
Aang's abilities as an airbender are challenged by a king.
In a nearby Earth Village, the gang meets a teenage earthbender named Haru. This village lives in fear of the Fire Nation, for soldiers there capture any earthbenders they can find.
Aang and friends visit a village being terrorized by an angry spirit. Iroh is captured by Earth Kingdom soldiers.
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.
After Katara attempts to teach Aang waterbending, but realizes that he is learning it much faster than she is, she is desperate to improve her abilities. When Katara inadvertently stumbles across a waterbending scroll that can help improve her ability while Aang is looking at a pirate’s store, she decides to steal it after she realizes that she couldn’t hope to afford it; but will she be capable of stealing from the pirates without causing herself and her friends trouble?
It's all about instincts...While traveling towards the North Pole, the group almost gets captured by the Fire Nation. However, when a charismatic young man and his band of rebels attack the Fire Nation camp and rescue them, they learn that they are trying to resist the Fire Nation’s motives to expand their territory. Katara and Aang really enjoy their time with the band of rebels, but Sokka soon discovers that they aren’t as noble as meets the eye.
While on their way to the North Pole, Aang and his friends arrive at a giant canyon where two groups of refugees are bickering over who should get to go across. Aang decides to walk across with the two groups to ensure they don’t fight one another. However, he soon learns that the two tribes have been feuding for one hundred years and they both believe their actions are justified. But when the predators inside the canyon start to come out, Aang is stuck trying to defend both tribes from each other and the vicious wildlife.
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 life before he was frozen in the iceberg.Meanwhile, Prince 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.
While Aang, Katara and Sokka are traveling, Sokka gets a fever. Katara and Aang try to help Sokka, when only Katara 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.Will Aang save Sokka and Katara in time?And who is this strange figure wearing a blue demonic looking mask?
When the group tries to help a man who is being attacked by a platypus-bear, they discover that the local town has a fortuneteller named Aunt Wu in it, who has been forecasting the town's fate for years. But when Sokka and Aang discover one of the fortuneteller's most vital predictions is dead wrong, they have to develop a plan to convince the stubborn townspeople that their beloved Aunt Wu was wrong.
Aang feels neglected as Katara and Sokka reunite with Bato, an old friend of their father’s from the South Pole. They begin to reminisce on their times in the past while they wait for a message to arrive from their father; in which Aang believes Katara and Sokka will abandon him and go out to find their father should the message arrive. However, when the messenger gives Aang the message to give to Bato, Aang betrays his friends in a way Katara or Sokka could never imagine. However, when Zuko recruits a bounty hunter named Jun to track Aang down, his friendship is put to the test as he must deal with the fact that he betrayed his friends while defending himself from yet another fight.
When Aang and his friends go to a Fire Nation town so that Aang can witness some firebending, 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 attempts to use this time to attempt to learn how to firebend. However, when the firebending master refuses to even see Aang, will Aang be able to prove he’s ready to learn how to firebend despite the fact that he lacks discipline?
When Aang and his friends hear rumors about surviving airbenders, they decide to stop by the Northern Air Temple on their way to the North Pole to see for themselves. What they find is a bunch of people who are not airbenders, but have mastered the art of gliding; though this upsets Aang because they have been defacing the temple. However, there was one part of the temple where nobody has been able to enter, and what Aang and his friends discover inside spells oncoming conflict.
When Aang tries to find the north pole, he is found by the north pole instead. When they are taken there Aang and Katara are eager to find a water bending master only to find that girls are not allowed to learn waterbending.
Zhao begins to launch his attack against the Northern Water Tribe. As the walls of the prestiged city begin to fall, the Avatar taps into the spirit world and seeks the help of one of the oldest spirits, in hopes of saving one of the most prominent areas of the world.
Aang returns from the spirit world to a big surprise. Meanwhile, Zhao and his forces continue to press deeper into the Northern Water Tribe. What could possibly stop the fire nation from destroying this tranquil region? If Zhao has his way, nothing. Also, Iroh makes a powerful stand and Zuko struggles to keep his plan intact.
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 the shocking news the gang have just discovered, 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.
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 and only Aang and the gang can save them.
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.
In search for an Earthbending teacher for Aang, the kids go to an underground Earthbending tournament called Earth Rumble 6, where they encounter 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 there are complications with Toph's family.
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.
Tired from trying to escape a machine that shows up every time they try to sleep, Aang and the gang have to escape Azula and her team, but their exhaustion leads to a tight situation. Meanwhile, Zuko must deal with something personal. And Iroh bonds with an unlikely individual.
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.
When Aang and his friends find a professor who knows of a library that contains information about the world, Sokka decides to go there to hopefully 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 have kidnapped Appa?
Aang searches for Appa, while Katara struggles to keep everyone together so they can survive in the vast desert while Sokaa supposedly gets "high" off Cactus juice in the desert.Meanwhile, Iroh and Zuko seek help from an ancient secret society.
After getting tickets for the ferry headed to Ba Sing Se, the gang meets an old friend. They skip the ferry ride to help some refugees, one of which is going to have a baby, get to Ba Sing Se. They must lead the refugees through the Serpent's Pass, a dangerous mountain-side path surrounded by water. After arriving at the great wall of Ba Sing Se, Aang and the gang discover that the Fire Nation has constructed a great drilling machine to penetrate the wall. The drill is also followed by an army of Fire Nation troops. Also, Zuko and Iroh are having trouble hiding the fact that they are both Firebenders.
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.
In this special episode, we flash back to the moment Appa was stolen, find out where he has gone, who he has met along the way, and—most importantly—where he is now.
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, Uncle Iroh is offered his own tea shop in the upper ring, and Zuko discovers the avatar is in 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.
Aang awakens to find himself aboard a captured Fire Nation ship with a full head of hair and sustaining serious injuries from the previous battle for Ba Sing Se. At his side are Katara, Sokka, and their father Hakoda who recount the events that led the four to the ship and contemplate their next move. Aang struggles to fight his own desire to face the Fire Lord before he is ready. Meanwhile, the once exiled Prince Zuko deals with his own issues as he makes his long-awaited journey home, with the fear of his father's rejection hanging over his head.
To better blend in as Fire Nation citizens, Aang enrolls in a Fire Nation school, giving himself an opportunity to learn more about the Nation while at the same enjoy life as a normal kid for the first time since he discovered he was the Avatar. Meanwhile Zuko, growing more and more paranoid about the Avatar's false demise, brings himself to confronts his imprisoned uncle.
When the gang arrives at a suffering fishing village, a mysterious spirit appears to help the villagers.
Feeling as though he isn't contributing enough to the group, Sokka seeks out an elusive swordsmaster from whom he can learn the ways of the blade.
Zuko, Azula, Mai and Ty Lee take a vacation to ember island. In the process, they come to learn more about themselves and each other as well as their desires for the future. Elsewhere, Aang and others face off against a new adversary.
The tale of Avatar Roku and Fire Lord Sozin is revealed to Aang and Zuko by different sources. Both learn about themselves and are shown the origins of the war.
When Katara expresses her disapproval to Toph's new way to make quick cash, the group finds her too motherly and tension grows between Katara and Toph. When Katara finally decides to participate in this scam to disprove Toph's accusations, they are left vulnerable and are forced to face the dire consequences.
The gang investigates the bizarre disappearances taking place within an eerie town.
Four days prior the invasion, Aang becomes nervous over his soon-to-come confrontation with the Fire Lord. His anxiety gets the better of him as he begins to suffer from outrageous nightmares and hallucinations. Meanwhile, Zuko becomes upset to learn that he was not informed about a war meeting.
Zuko makes a decision about his future. Aang reunites with many of his old friends in a full-scale invasion of the Fire Nation capitol to coincide with an eclipse which will remove the Fire Nation's powers. The invasion seems to be succeeding until Aang learns that their arrival was anticipated. Zuko confronts his father.
Aang and the group arrive at the Western Air Temple, with Zuko in pursuit. Zuko only wishes to be accepted, and help the Avatar, but will the group allow him to teach Aang firebending?
While teaching Aang firebending, Zuko finds that he has lost all his firebending skills. Now to regain his powers, Zuko and Aang must seek the original source of firebending within the ruins of a lost civilization.
Sokka and Zuko head to the Fire Nation's most heavily guarded prison, the Boiling Rock, in hopes of finding and breaking out the captured invasion force. The escape is planned and the heroes attempt to break from the prison that very day. But problems come when Azula, Mai and Ty Lee arrive at the prison.
Katara decides to confront the Fire Nation soldier responsible for her mother's death. Aang tries to talk her out of it, and Katara later realizes he was right and learns a lesson about life and herself.
A play recounting the gang's adventures does not sit well with Aang and his friends, except for Toph who enjoys it very much. Meanwhile, Aang confesses his love to Katara, but the response is ambiguous.
Sozin's Comet is only three days away. Zuko tells the others what the Fire Lord plans on the day of the comet and the gang realizes that they must stop him before then. But Aang doubts that he can do what is expected of him. Aang awakes on a mysterious island and confronts his past lives for advice on how to stop the Fire Lord without killing him. The rest of the group searches for Aang. Zuko battles his sister with Katara's help for the right to be named Fire Lord. Elsewhere, Aang meets Ozai just as the comet arrives. Aang's moment of truth arrives. Can he defeat Ozai, the Phoenix King? Will he be forced to take a human life? All the characters face their greatest challenges.
