Sadly, we have now arrived at the final season of Avatar: The Last Airbender: Book 3: Fire. The season starts with Aang waking up and discovering he has hair (!). He and his friends are riding in a stolen ship and wearing Fire Nation clothes and the rest of the world thinks he’s dead (!!). He soon realizes that this is an advantage because now he can pull a sneaky little sneak attack later. Aang, Katara, Toph, and Sokka arrive in the Fire Nation and Aang is mistaken for a school boy and is forced to go to school. There he learns the Fire Nation pledge of loyalty and is exposed to all the Fire Nation propaganda. As the gang makes their way across the Fire Nation, Sokka starts to feel left out because he’s the only one in the group that can’t bend. He finds a sword master named Piandao to train him, but first he has to do seemingly irrelevant tasks like painting and rock-gardening but then realizes these tasks were helping him learn the whole time (very Karate Kid-esque).
Meanwhile, Zuko and Azula have returned home as heroes and Zuko’s father congratulates him on killing the Avatar. Zuko realizes Azula gave him the credit because she has some sneaky ulterior motives (everyone is veeeeery sneaky in this season). Zuko starts to think that the Avatar isn’t actually dead, so he hires an assassin to kill Aang. (Also, Iroh is in jail and planning his escape. Like I said before: everyone is being sneaky.) While on a forced vacation, Zuko realizes that he’s mad at himself because he can’t tell the difference between right and wrong anymore—he also discovers that he’s in love with one of his sister’s best friends, Mai. Elsewhere, Aang gets attacked by Zuko’s assassin.
Both Aang and Zuko learn about the friendship between Avatar Roku and Firelord Sozin. Sozin told Roku that, since the Fire Nation is the pinnacle of civilization, they should control the world. As the Avatar, Roku knew the importance of balance, so when Sozin took an Earth colony, Roku threatened to kill him if he tried again. When the volcano on Roku’s island erupted, Sozin came to help, but realized that with Roku gone he could rule the world, but then once he lets Roku dies he feels like a huge jerk (because he is). Iroh tells Zuko that since he’s the great-grandson of both Roku and Sozin, he’s the only one who can resolve the conflict and restore balance and peace to the world.
While in a Fire Nation town, the gang discovers that there have been strange disappearances during the full moon. They befriend an old innkeeper named Hama who reveals she is a waterbender from the Southern Water Tribe. She becomes Katara’s mentor and reveals to her that she was a Fire Nation prisoner. Katara discovers that Hama is enacting her revenge by kidnapping civilians with bloodbending—a technique that can only be used by a skilled waterbender during a full moon (also the sound effect for it is disgusting). Katara is horrified, but ends up having to use this technique in order to save Aang and Sokka. Then she feels really bad about it.
The day of the solar eclipse, and therefore the invasion, is four days away and the gang forms a little ragtag team of allies with various people they’ve met on their adventures. Aang’s worried he’s going to die, so he finally kisses Katara again. They successfully infiltrate the Fire Nation capital and Aang gets to the palace only to find out that there’s no one there…awesome. Sokka, Toph, and Aang go searching for the Fire Lord, but can only find Azula in an underground bunker.
In a different bunker, Zuko tells his father, Ozai, that the Fire Nation only spreads fear and hate, that the Avatar is alive, and that he is running away to go help him restore peace. Ozai does not take this news very well and tries to kill Zuko with lightening, but thanks to his training with Iroh, Zuko is able to redirect it. Aang is forced to let his team get captured, but he flees with his friends to the Western Air Temple with Zuko trailing behind them. Once he catches up with them, the gang is not too keen on letting Zuko join them, but once he saves them from the assassin that he had sent after them in the first place (who is still really hung up on his mission), they see he has changed for the better—except for Katara who threatens to kill him at the slightest sign of treachery (which is a liiiittle bit much, but whatever girl, you do you).
Zuko tries to teach Aang how to firebend, only to discover that he has lost the ability. Toph suggests that they try learning from the original source of firebending—the dragons—so, Zuko and Aang travel to the nearby ruins of the Sun Warrior civilization. They discover that the Sun Warriors are actually still alive and are told they must carry a sacred flame up the mountain to meet the dragons. They almost succeed, but then the flame goes out. They perform a dragon dance that they learned while exploring the ruins and the last two dragons reveal themselves. The dragons tell the boys that the true secret to firebending is life and not destruction. With this little nugget of knowledge, they are both able to firebend again.
Sokka and Zuko infiltrate a Fire Nation prison to find Sokka and Katara’s father, but get trapped on the island. They come up with a plan to escape, but before they can, a new batch of prisoners arrive that includes Sokka’s father so they decide to stay. While creating a new plan, Mai shows up and demands to know why Zuko left her, so he tells her that he’s trying to save the world. Mai thinks that this is an acceptable excuse and helps them escape. Azula is pissed that Mai would help Zuko, but Mai’s in love with him so she doesn’t care. They start fighting and Ty Lee (who is another one of Azula’s crazy friends) tries to intervene so Azula has them both arrested.
Aang has decided to fight the Fire Lord after Sozin’s Comet passes, but then Zuko reveals that Ozai intends to level that entire Earth Kingdom continent with the extreme power that the comet gives him. With this new knowledge, the gang begins a frantic training regimen while Aang struggles with his moral code. His friends want him to kill Ozai, but Aang clings to the pacifist beliefs of his Air Nomad heritage. Meanwhile, Ozai declares Azula to be the new Fire Lord, and declares himself “Phoenix King:” ruler of the known world (kewl).
In his sleep, Aang walks to a mysterious island that appears suddenly in the ocean. In the morning his friends frantically search for him and come across a bounty hunter named June who offers to help. Aang wakes up on an island in the middle of the ocean with no memory of how he got there. While on the island, Aang seeks guidance from his past lives, but they also insist that he must take action against the Fire Lord. He then discovers that the island is actually a giant lion-turtle (not a real animal). He asks the lion-turtle what he should do, and the turtle responds with a crazy little poem and touches Aang on the forehead and on the heart and a crazy little green glow starts to happen. This was apparently super useful to Aang because then he knows what he has to do.
June the bounty hunter is unable to find Aang, so Zuko asks if she can help him find his uncle instead. She leads them to Ba Sing Se where they meet King Bumi, Master Pakku, and Master Piando who are members of the Order of the White Lotus and—SURPRISE—Iroh is there leader. After a super heartfelt reunion, the team decides to split up. Zuko and Katara (who are bffs now) will go to the capital of the Fire Nation to take out Azula; Sokka, Suki (a Kyoshi worrier from Book 1), and Toph will attempt to deflect the Fire Nation airships impinging on the Earth Kingdom; and Iroh is to lead the Order in the liberation of Ba Sing Se.
Sozin’s Comet arrives and the newly titled Phoenix King Ozai is preparing to destroy the Earth Kingdom. Meanwhile, Azula’s mental stability is deteriorating as her coronation as Fire Lord approaches. Zuko and Katara confront her right when she is about to be crowned—super dramatic of them—and she challenges Zuko so an Agni Kai (a firebending battle). Zuko is winning, but then Azula plays dirty and throws lightening at Katara. Zuko dives in the way and is gravely injured. Elsewhere, Aang is dueling Ozai, but isn’t accomplishing anything since he still refuses to kill him. Meanwhile, Sokka, Toph, and Suki are attempting to halt the airship fleet but are soon separated, while the Order is battling for Ba Sing Se’s freedom.
They are eventually successful, as are Sokka and Co. Over in the capital, Katara freezes and chains down Azula which triggers a full psychotic breakdown. She then uses her healing powers to revive Zuko. Over on the battlefield, Ozai accidentally causes Aang to enter into the Avatar State and he easily starts to overpower Ozai, but still refuses to kill him. Instead, with the knowledge he got from the lion-turtle, he uses some new kind of bending to take away Ozai’s firebending ability.
The newly appointed Fire Lord Zuko declares the war officially over and they all celebrate together in Iroh’s tea shop in Ba Sing Se. Aang and Katara share a kiss before the sunset and then, bam: Avatar: The Last Airbender is officially over. But fear not, because the lovely creators of the show also created a comic book that follows Aang and friends on all their adventures after the war.