Avatar: The Last Airbender Season Three (2007) created by Michael Dante DiMartino and Bryan Konietzko
Avatar Aang is recovering from a near-mortal wound. He and his friends are hiding out in the Fire Nation, getting ready to attack on the day of an upcoming eclipse, hoping to knock out Fire Lord Ozai. Firebenders gain strength from the sun, so the eclipse will weaken them substantially. If successful, Team Avatar won't have to worry about the return of Sozin's Comet, which promises to give the Firebenders a huge advantage. Ozai plans to finish his world-wide conquest when the comet returns, creating a hard deadline for Team Avatar if the eclipse plan does not work.
Meanwhile, Zuko has returned to the Fire Nation and the favor of his father since he "killed the Avatar" at the end of last season. His victory feels hollow to him even before he finds out the Avatar is still alive. His betrayal of Team Avatar and especially of his uncle Iroh weighs heavily on his mind. Is his destiny really to become the next Fire Lord? Will his crazy sister Azula let it happen?
As in other seasons, the story moves at a good pace. It's not too fast, allowing the characters to develop and more of the world to be explored. It's not too slow, keeping up the sense of excitement and peril. The story weaves in a lot of the old, familiar characters for the big fights during the eclipse and during the return of the comet. The narrative comes to a climax in the last episodes that is very satisfying.
The show also maintains the quality of writing. The characters are rich and conflicted. Zuko has a crisis of vocation, realizing that maybe he is not meant to be on his father's side. He has to swallow a lot of pride and overcome a lot of mistrust from Aang and Katara. His character arc is my favorite part of the show. Aang also deals with a huge conflict. Everyone tells him he must kill Fire Lord Ozai but his Air Temple training teaches him that all life is sacred. As a twelve-year old (if you don't count the hundred years of suspended animation in the ice berg), he has a burden that even adults would struggle with. The show doesn't give quick, easy answers to these problems. Though set in a fictional world, the show has a lot of moral truth. The writing is great.
Highly recommended--this is easily the best kids' show I have seen, and in my top ten shows of all time.