Ten years ago today, Nickelodeon aired the four-part finale of their fantasy-adventure epic, Avatar: The Last Airbender. The quartet of episodes combined to form what was essentially a 93-minute movie. With “Sozin’s Comet,” as it was called, creators Bryan Konietzko and Michael Dante DiMartino had an impossible task before them: wrap up and tie together a hugely ambitious, sprawling narrative, one that involved a litany of primary characters and spanned an entire fictional planet. The part that’s still stunning, ten years later, is that “Sozin’s Comet” didn’t just accomplish the impossible. It gave us one of the most moving, immersive, gorgeous pieces of television ever produced.

Before we can get into what makes Avatar’s finale such a landmark moment, let’s set the scene, both in our world and in the world of Avatar.

I. Previously on Avatar

“Long ago, the four nations lived together in harmony. Then, everything changed when the Fire Nation attacked.” Avatar’s famous opening narration gives us the basic facts: this is a world with four elements and four lands: the Fire Nation, the Earth Kingdom, the Water Tribes, and the Air Nomads. Certain people are born with the ability to manipulate, or “bend,” one of these elements; for example, an earthbender could levitate a stone and send it flying toward you.

Only one person in the world is born with the ability to bend all four elements: the Avatar. A sacred, revered being, the Avatar’s role is one that passes on, in a naturally occurring cycle, between the elements. Once an Avatar dies, they are reincarnated into a new person in a different part of the world.

The current Avatar, a child of the nomadic, monastic air peoples, is the twelve-year-old Aang. Along with his friends, waterbender Katara, earthbender Toph, and nonbenders Sokka and Suki, Aang traverses the world, tangling with the Fire Nation every step of the way. In order to defeat the Fire Lord Ozai and put a stop to the Hundred Year War, Aang sets out to accomplish his destined task: mastering all four elements.

There’s one final piece that completes this puzzle: Zuko. The crown prince of the Fire Nation, Zuko once spoke out of turn at a war summit, causing his father, Ozai, to challenge the thirteen year old to a ritual duel, called an Agni Kai. Zuko refused to fight, causing Ozai to severely burn his face and banish him from the Fire Nation. Zuko was told that the only way he could return and regain his honor would be to capture the long-absent Avatar, the Fire Nation’s only remaining threat. Still bandaged from his own father’s fire, Zuko angrily sets sail with his worldly, light-hearted Uncle Iroh in search of Aang.

II. Nickelodeon and Avatar

In the fall of 2007, the third and final season of Avatar: The Last Airbender premiered. Nickelodeon aired episodes weekly from September 21st to November 30th, on which the two-part mid-season finale, “The Day of Black Sun,” aired. Avatar was no stranger to multi-part episodes, having established a pattern of diptychs placed at the middle and end of both seasons one and two.

Ten episodes remained in the series, to be aired the following summer (the only time the show had gone this long between premiering episodes was between seasons two and three). The particularly noteworthy decision that Nickelodeon made, however, was to show all ten episodes in the space of one week. The first six were aired between July 14-18, and the four-part finale aired at 8:00 EST on July 19th, 2008, the end of a three and a half year journey for viewers (and a six year journey for the show’s creators).

In the show’s artbook, Avatar: The Last Airbender – The Art of the Animated Series, co-creator Bryan Konietzko said that his main goal for the finale “was simply to finish telling the whole story. Beyond that, I wanted to make the finale better than anything we had ever done.”

Every aspect of the finale’s production was aimed at making it a singular experience in the run of the show. The season had been budgeted to allow for unique indulgences in the finale, such as a live string ensemble in the place of the show’s typical MIDI-stringed score. It was conceived as a movie, and as such, the Avatar crew gathered to watch the complete “Sozin’s Comet” in the Paramount Pictures theater before it premiered.

So what ended up happening in the finale? How did it all end?

III. Sozin’s Comet

Zuko, the banished fire prince, has finally seen the error and the evil of his nation, and joined Avatar Aang’s group. Their aim is to take down the Fire Lord, who plans a devastating, war-winning attack on the day of a comet. The flaming comet’s proximity gives firebenders extreme, once-in-a-century strength, and Ozai plans to use it to conquer the world once and for all.

Zuko’s sister Azula, a cunning manipulator and an extremely gifted firebender, has been the show’s most effective and engrossing antagonist. She hunts the Avatar with her trademark blue fire while also haunting Zuko, a reminder of his past life as a prince. When the time for the invasion has come, Fire Lord Ozai leaves Azula behind in the Fire Nation, giving himself the new title of Phoenix King as he heads off in an airship. The slight causes Azula’s already-fragile self image to shatter, leaving her unhinged and even more dangerous than before.

The story solidifies into four parallel climactic battles: Avatar Aang vs. Phoenix King Ozai, Zuko vs. his sister Azula, the remaining Team Avatar members vs. a fleet of Fire Nation zeppelins, and Zuko’s beloved Uncle Iroh liberating the occupied Earth Kingdom city of Ba Sing Se. If it sounds like a complex, dramatic undertaking, that’s because it is. Each of the show’s primary threads are resolved simultaneously, a carefully orchestrated climax of both external action and internal conflict.

The story of Avatar: The Last Airbender, as intricate and expansive as it is, can really be boiled down to its two most important characters: Aang and Zuko. Here, finally, we come to it: the way that “Sozin’s Comet” finishes the stories of Aang and Zuko (narratively, but also stylistically) is what makes the finale so special, a perfect end to an already great series.

IV. Aang

Aang, as a character, is conceived as a set of contradictions. He’s a light-hearted, light-footed jokester with the weight of the world on his shoulders. He’s an airbender in a world where airbenders don’t exist, having been wiped out completely due to a horrific genocide a century earlier. And he’s a peaceful nomad raised by monks, tasked with killing an out-of-control tyrant.

One of Aang’s most important characteristics is that he has deeply held convictions about the role of violence. Two episodes before the finale, Katara tracks down her mother’s killer and ultimately decides to show him mercy. Zuko says to Aang, “you were right about what Katara needed. Violence wasn’t the answer.” “It never is,” Aang says. Zuko: “Then I have a question for you. What are you going to do when you face my father?”

Much of Aang’s journey through the four parts of “Sozin’s Comet” are spent agonizing over this question. Even facing total destruction, Aang feels he cannot justify the killing of Ozai. He asks his own past lives, the previous Avatars, for their advice, and they all feel that in such an extreme situation, the act of killing is permitted by the importance of the greater good.

It’s Aang’s insistence on his ideals that affords him the opportunity to find a third option. Aang has traveled between realms on numerous occasions during the run of the show, and his increasing knowledge of the spirit world comes to a head when he is granted a final piece of knowledge by the world’s oldest living creature: a gigantic, island-sized lion turtle, an ancient being from the time before bending.

Aang learns that as the Avatar, he has the power to remove a person’s bending ability, rendering them essentially powerless. In the climax of his battle with Ozai, he is nearly consumed by Ozai’s energy, but succeeds in taking away the tyrant’s firebending, winning the fight without killing.

The lion turtle’s existence had been (very) subtly hinted at throughout the series, but some viewers’ subsequent claims of “deus ex machina” were well-founded. That said, I think its appearance does actually work, in a few different ways. One, as I’ve already laid out, is that it’s a culmination of Aang’s commitment to the ideals of his people, people who were wiped out by the very entity he now faces. It’s a common concept, but still important: what good is mercy if there are exceptions? Aang knows that the only way to end a hundred years of death and war is through an act of true mercy, not by perpetuating a cycle of violence.

In a more meta-textual sense, I like the lion turtle because it combines Avatar’s two different modes: serial installments in the grand tale, and episodic, self-contained stories of our heroes’ adventures. It’s important to not forget that Avatar was, in its promotion, production, and release, a kid’s show on Nickelodeon. It’s not a great show despite that fact; it’s a great show, at least in part, because of that fact.

Although the broader, series-spanning narrative of Avatar is what gets most praise and attention in retrospect, the way it excels in the self-contained episode format is another of its strengths. When looking at Avatar as a whole, it’s easy to see the lion turtle as an extremely late addition with huge, convenient ramifications. But when viewing “Sozin’s Comet” as a super-sized episode, it feels like a fascinating new character-of-the-week. Nowadays, we’re conditioned to full-on serials like Game of Thrones, which spend the season setting up dominoes only to give a little tap and watch them fall in a season finale. But I’m not sure that a series like Avatar should, or even can, be judged by that same metric.

In defeating Ozai, Aang finally fulfills the promise of the show’s opening narration: “I believe that Aang can save the world.” But while Aang, who gives the show its title, is the ostensible protagonist, the character with the most complete and transformative arc across all three seasons is Zuko.

V. Zuko

When we finally arrive at “Sozin’s Comet,” Zuko has come out on the other side of a long personal exploration. He began as a bitter young man, banished from his home at the age of thirteen, on a single-minded mission to capture the world’s only chance at hope. By the series’ end, he’s traveled the world, seen the ugly truth about his nation, and learned countless lessons of kindness and patience from his Uncle Iroh. In the season two finale, Zuko’s crucial moment of weakness causes him to walk back his growth and betray his uncle, a decision he instantly regrets. He commits himself to helping the Avatar take down his father.

The reunion between Zuko and Uncle Iroh in “Sozin’s Comet” is probably the most affecting, emotional scene in the entire series. Zuko spills his heart out, begging for the forgiveness of his only real father figure. Iroh pulls him into a tight embrace. And then, as Aang departs to face Ozai, the time has come for Zuko to face his true adversary: Azula.

You can’t understand Avatar without Zuko, and you can’t understand Zuko without Azula. Azula had always been the firebending prodigy, the only bender who naturally creates blue fire. Throughout the show, we’ve seen the way that Azula mistreats her own family and friends, borne from a deep-set insecurity. Her relationship with their mysteriously-disappeared mother is central to Azula’s paranoia: in “Sozin’s Comet,” Azula looks in the mirror and sees the image of her mother looking back at her. She shatters the mirror in a rage.

Zuko and Katara confront Azula, who is about to be crowned Fire Lord after their father’s self-appointed ascension to the rank of Phoenix King. Always attempting to play things to her advantage, she challenges Zuko to an Agni Kai, a formal one-on-one fire duel. The very duel in which, several years prior, Zuko’s own father had given him his trademark facial scar.

Konietzko has described the Agni Kai as the “emotional climax of the series.” He’s right, because even though the world-consequences climax is the battle between Aang and Ozai, Zuko’s remarkably full internal arc gives this sequence an even higher sense of stakes. Aang’s battle is for the fate of the world, but Zuko’s battle is for the soul of the world. And it’s here that we get the single most stunning combination of animation and sound that Avatar has to offer.

For the finale, composer Jeremy Zuckerman was given the ability to write for and record with a string ensemble. Zuckerman and collaborator Benjamin Wynn’s work on Avatar had always been top-notch, creating memorable themes with unique instrumentation. But they jumped at the chance to up their game for the finale, writing haunting, atonal pieces and soaring, victorious explosions. But when Zuckerman conferred with Konietzko on what to do for the Agni Kai scene, they decided on a more muted, somber tone. Konietzko cited Ghost in the Shell and Blade Runner as influences for using a more low-key piece during a high-intensity action sequence.

Once it begins, you just feel it: it was always meant to end this way. Azula’s blue fire billows off of Zuko’s orange fire, a color contrast that will be paralleled in Aang’s final struggle against Ozai. We cut to an extremely wide shot of the royal city, and the plumes of blue and orange flame are visible in the distance as Zuckerman’s funereal strings drone on.

There’s no better distillation of what Avatar is, or even of what animation can achieve as a medium: a perfect confluence of character, theme, art, music, and drama. Azula’s final act of deception is to attack Katara, and Zuko jumps in the way to save her, a completion of his series-long journey toward selflessness.

VI. Legacy

Avatar: The Last Airbender ended ten years ago today. In 2018, its reputation as a classic only continues to grow. There is so much to dissect and appreciate about Avatar that goes beyond its finale: Katara, for example, whose own arc had mostly finished before “Sozin’s Comet.” The terrific character of Toph Beifong, the genius, blind earthbender, somehow managed to go almost completely unmentioned here. And that’s to say nothing of the fascinating stew of Asian religious and cultural influences that went into creating the world of Avatar (each of the four elemental forms of bending is based on a different martial art!).

Avatar’s main legacy, though, is its own sequel, The Legend of Korra. Less than four years after the airing of “Sozin’s Comet,” Konietzko and DiMartino’s follow-up series premiered its first episode. Korra is a masterpiece in its own right, with different strengths and weaknesses than its predecessor.

The Legend of Korra came to an end in December of 2014, rushed and discarded by Nickelodeon. It couldn’t possibly have had a finale as game-changing as “Sozin’s Comet,” though, could it? Believe it or not, it did, only it proved to be a game-changer of a different type, breaking down industry barriers of on-screen representation.

What Korra’s finale could not do, however, and what almost no television finale has done since, is weave every disparate element together in so rich and rewarding a tapestry. The embrace between Avatar Aang and newly-crowned Fire Lord Zuko in the episode’s last moments gives the viewer a feeling of finality and satisfaction akin to a runner, collapsing at the finish line, having set a new world record. It’s a deep, true joy.

Ten years on from “Sozin’s Comet,” the future of the post-Avatar world is still bright. Konietzko’s graphic novel series Threadworlds is coming out sometime in the near future. The Korra and Avatar alumni-helmed Voltron: Legendary Defender is on Netflix (and really good, if you haven’t watched it), and a new Netflix series from Avatar head writer Aaron Ehasz was just announced called The Dragon Prince. But even as we continue to get more and more Avatar-influenced shows, I’m reassured in the knowledge that Avatar itself, and its finale in particular, will continue to be examined and discussed for years to come.