- This article is about the second episode of the Book One: Water finale. For the first part of the finale, see "The Siege of the North, Part 1". For the battle, see Siege of the North.
After successfully capturing Aang, Zuko struggles to find shelter on the frozen waste of the North Pole. Meanwhile, as the Fire Nation invades the city, Sokka, Katara, and Yue search for the prince and Aang. As Aang's returning spirit guides them to their location, they save him and return to the Spirit Oasis, though are too late to stop Admiral Zhao from slaying the Moon Spirit's mortal form, causing the moon to vanish and all waterbenders to lose their ability to bend. Enraged, Aang combines himself with the Ocean Spirit, La, and obliterate the entire Fire Nation armada. Meanwhile, Princess Yue, who was imbued with some of the energy of the Moon Spirit when she was a sickly newborn, sacrifices her life to restore it to life. As the moon returns in the sky, La releases Aang, though upon retreating to the oasis, ambushes Zhao, who refuses to allow Zuko to save him, and drags the admiral under the surface with him. After the battle's conclusion, Team Avatar journeys on, while Zuko decides to call off his pursuit of the Avatar for a while. Meanwhile, in the Fire Nation, a young woman receives an assignment from Fire Lord Ozai.
Sokka, Katara, and Princess Yue set out on Appa in search of Aang, as the Fire Nation continues its attack on the Northern Water Tribe. As Zuko carries Aang across the polar ice cap, Aang's spirit is in the middle of a swamp in the Spirit World. In search for help with finding the Moon and Ocean Spirits, he approaches a baboon spirit who is meditating nearby, though the spirit grows annoyed over the intrusion and tells Aang to leave him alone. As Aang fails to adhere the request, a glowing speck flies by, and the baboon spirit exasperatedly suggests that Aang chases it, implying that it may be able to help him. Aang chases the glowing speck through the Spirit World, though when he finally manages to grasp it, the branch on which he is standing disappears, and he falls into the water. Avatar Roku's image appears as a reflection in the water, and he greets Aang.
In the mortal world, the ice on the frozen waste begins to give way under Zuko, who is carrying Aang over his shoulder. Dashing frantically across the fracturing surface, he manages to avoid falling through the ice. While catching his breath, he sees a cave a short distance from where he is and drags Aang's body into the shelter, where he binds him.
Aang's spirit tells Roku that the Water Tribe is under attack and he needs help locating the Moon and Ocean Spirits. Ascending from the water and materializing in front of Aang, Roku tells him that the spirits in question crossed over into the mortal world near the beginning of time. Knowing only of one spirit old enough to be of any help, Roku guides his successor toward Koh, though warns him to be careful, as Koh is a dangerous and volatile spirit; if Aang shows any emotion when facing Koh, the spirit will steal his face. Aang, while horrified by the possibility, nods in understanding.
As Sokka, Katara, and Yue continue to look for Aang in the blizzard, Zuko talks to an unconscious Aang. He laments over the irony of finally succeeding in capturing the Avatar but being prevented from returning to the Fire Nation by the blizzard and muses that there is always something. Zuko compares Aang to his sister, noting that everything always came easy to her, from being a firebending prodigy to being adored by all. Bitterly recalling his father's statement that she was born lucky, while he was lucky to be born, Zuko denounces his need for luck as his struggles have made him strong.
Despite the waterbender warriors' efforts, Fire Nation troops move further into the Northern Water Tribe. While spectating the battle from the deck of their ship, Iroh reminds Zhao that if the Water Tribe is not subdued by the rise of the full moon, the waterbenders will be undefeatable. Zhao says he is in control of the situation, and that he plans to remove the moon from the battle. Before he can explain himself to Iroh, they are interrupted by Hahn, who promptly attacks Zhao, though the admiral nonchalantly throws him overboard. Continuing as if nothing had interrupted their conversation, Zhao explains that years earlier, while serving as a young officer in the Earth Kingdom, he stumbled on the secret of the Moon and Ocean Spirit's mortal forms in an underground library. When he declares it is his destiny to kill the spirits, Iroh angrily informs him that the spirits are not to be trifled with. Condescendingly, Zhao tells Iroh he has heard tales of his journey into the Spirit World and assures him that the Moon and Ocean Spirits, having made the decision to give up their immortality to be part of the human world, will face the consequences of that decision.
Aang approaches a large leafless tree and notices another spirit in the form of a monkey. As Aang approaches and speaks to the monkey, it turns around, revealing that it has no face. Aang, terrified but determined, takes a deep breath, repeats Roku's instructions to himself, and enters the hollow tree, calling out to Koh. Suddenly, Koh, with a large centipede-like body and a face similar to a Japanese Noh mask, appears in front of Aang. As he switches faces, Koh explains to Aang that this is not their first encounter: one of Aang's previous incarnations tried to kill Koh over the stealing of a loved one's face. Koh continues to state how he is no longer concerned for what Aang did in his past life. Aang takes a breath in to gather strength and to remain composed as Koh tries to manipulate him.
At the same time in the natural world, Aang's body also takes a deep breath as Zuko looks on; Zuko says that it appears that they will be in the shelter for a while. Elsewhere, Yue tries to comfort Katara by saying Zuko and Aang could not have escaped. Katara states that her worry is not that Zuko will escape, but that he will fail to do so, thereby jeopardizing Aang's life. Sokka assures Katara that Zuko will not give up, and that both he and Aang are alive and will be found.
Menacingly, Koh asks, "So. How may I help you?" Aang tells Koh of his need to find the Moon and Ocean Spirits. Koh tells Aang the spirits' names – Tui (push) and La (pull). Aang explains that an entire culture may be destroyed if he does not get the spirits' help, to which Koh replies that the opposite is true: it is the spirits who are in need of his help, as someone is planning to kill one of them. Aang asks how he can find the spirits to protect them, to which Koh responds by telling Aang that he has already met them. As Aang realizes the spirits' mortal identities upon hearing Koh's analogous reference to yin and yang, his expression changes, and he narrowly avoids losing his face; Koh, hearing the change in Aang's tone, whirls around to face him, only to find that Aang has caught himself. After leaving a somewhat disappointed Koh behind in his tree, Aang explains to Roku's reflection that the spirits are in trouble and he needs to get back to the mortal world. Roku tells Aang that an old friend will help him back, and Hei Bai appears; climbing on the spirit's back, they rush away into the wild.
At the Water Tribe, night has fallen, and the full moon has risen, enhancing the power of the waterbending warriors as they do battle with the soldiers of the Fire Nation. Zhao and his search party depart his ship in search of the Spirit Oasis. Zhao declares that when they get there, "We're going fishing."
Hei Bai takes Aang back to the gate at which he entered the Spirit World and breaths out a light toward Aang, sending his spirit to the mortal world. As he crosses out of the Spirit World, the baboon spirit, still meditating nearby, comments, "Good riddance". Temporarily changing into his monstrous, angered form, Hei Bai, seemingly upset by the comment, blasts him off his rock before returning to his normal appearance.
Aang's spirit returns to the oasis in the Northern Water Tribe, but he finds, to his dismay, that his body is not there. Aang's spirit is then pulled to his body through the sky, rushing to his body in the form of a streak of light. Katara, on Appa's back as she searches for Aang, sees and realizes it is Aang's spirit. They turn Appa to follow the light as it reaches the cave in which Zuko is sheltering with Aang's body. As his spirit rejoins his body, Aang's tattoos fade to blue and he sits up; after a short, curt exchange with Zuko, Aang proceeds to airbend a large gust of air; it throws Zuko against the side of the shelter and propels Aang out of the cave and into the snow. Zuko manages to catch the still-bound Aang, but Appa lands next to them and Katara jumps down. Zuko inquires if she came "for a rematch", to which Katara confidently replies, "Trust me, Zuko, it's not going to be much of a match." It takes mere seconds for her to force Zuko high into the air with a column of snow and smash him to the ground, knocking him out. As Sokka, Katara, Aang and Yue prepare to leave, Aang hesitates; refusing to leave Zuko to freeze to death, he lifts the prince's limp body into the saddle before they depart.
Reaching the oasis, Zhao removes the white koi from its pond; as he hoists it over his head in triumph, the full moon above transforms, turning from white to blood-red. Immediately, the waterbending warriors lose their bending abilities, and the Fire Nation troops begin to push forward. Yue, on Appa's back, begins to feel faint. When Sokka takes notice, she tells the others, and Aang concurs, saying he feels it as well. Yue then explains that the Moon Spirit restored her life as a baby, and that this is how she received her name; Yue – for the moon. Meanwhile, Zhao arrogantly applauds his own efforts to fulfill his "destiny", even speculating as to which names by which future generations will call him. His power-crazed musings are interrupted by Momo, who suddenly jumps onto his head, pulls at his hair, and flies over to Aang, who has arrived with the others and stands opposite Zhao. Aang pleads with Zhao to consider his actions: they will bring harm to all, not just those in the Water Tribe. Reinforcing the point, Iroh appears, affirming Aang's words and promising Zhao, "Whatever you do to that spirit, I'll unleash on you ten-fold." He then orders Zhao to release the fish, preparing to fight.
Zhao begrudgingly releases the spirit back into the water. However, in a fit of blinding rage, he attacks it with fire, killing it and effectively destroying the moon, which vanishes completely from the sky. Iroh, true to his word, unleashes his firebending on Zhao and his guards, easily defeating the soldiers but inadvertently allowing Zhao himself to escape. Iroh carefully lifts the burned white fish from the water as Yue mournfully states, "There's no hope now. It's over." In that moment, overcome with emotion, Aang goes into the Avatar State, offering a response: "No. It's not over." As he steps into the oasis. Katara tries to follow, but Iroh gently holds her back. As Aang stands in the oasis, the living fish begins to circle him; abruptly pulled under the surface, Aang merges with the Ocean Spirit, and the two leave the oasis, following the conduits of water outward into the city below, where they take the form of a massive koi fish and begin their assault on the Fire Nation invaders in the city. After wiping them out and clearing the city of enemy soldiers, they make their way toward the sea.
Meanwhile, Zhao slips through the deserted streets, trying to escape; he is suddenly attacked by a newly freed and infuriated Zuko. Shocked that Zuko is alive, Zhao further antagonizes Zuko by confirming that he tried to have Zuko killed; he also reveals that he knew that Zuko was the Blue Spirit, the one who stole the Avatar from him. Zuko counters that he had no choice, but Zhao tells Zuko that he should have accepted his fate as a failure and a disgrace, and they once again begin to fight.
In the oasis, where the group has given up hope of saving Tui, Iroh notices, with astonishment, that Yue has been touched by the Moon Spirit, and that as a result, some of its life force is within her; Yue affirms the conjecture, then decides that she should try to restore tui to life by giving hers to it. Sokka, upset by this idea, protests, saying, "Your father told me to protect you!" She calmly replies, "I have to do this," and places her hands on the dead fish. As her spirit leaves her body, she closes her eyes, exhales one last time, and collapses into Sokka's arms, dead.
Moments later, Yue's body disappears, and the fish, suddenly filled with life, glows as Iroh places it gently in the oasis. As the fish begins to swim, the oasis glows as well, and Yue appears above the water as a spirit, clothed in a flowing white dress. She tells Sokka that she will always be with him, kissing him one last time before disappearing; as she vanishes, the moon reappears in the sky, restoring the waterbenders' abilities.
Aang and La, in the meantime, have been laying waste to the Fire Nation's soldiers and navy, and have made their way to the ocean, destroying ships as they go. As the moon reappears, the Ocean Spirit acknowledges the moon's restoration and, ending its violent vendetta, places Aang atop the outer wall as it moves back through the Water Tribe city.
Zuko and Zhao are still dueling when Zhao, seeing that the moon has returned, shouts, "It can't be!" Without warning, the Ocean Spirit, taking the form of a giant hand, seizes Zhao and begins to pick him up. Zuko, forgetting the duel, tries to help Zhao, reaching out a hand to him, but Zhao stubbornly refuses to take it, and he is pulled beneath the water, where he disappears from view.
After the battle, Master Pakku announces plans to head to the Southern Water Tribe with other tribe members to help rebuild their sister tribe. Katara asks Pakku about who will oversee Aang's training, and Pakku tells her that Aang will have to get used to calling her 'Master Katara'. Chief Arnook quietly tells Sokka about a vision the spirits gave him when Yue was born: a young woman giving her life to become the moon. Sokka states that he must be proud; the chief replies that he is, but that he is also deeply saddened by her death.
Having rejoined Zuko on a raft, Iroh slyly says he is surprised that Zuko is not absorbed with capturing the Avatar. Zuko simply replies, "I'm tired," to which Iroh softly tells him, "Then you should rest. A man needs his rest." Zuko closes his eyes. Katara meets Aang on an overlook in the city, and they embrace; Momo and Sokka join the group hug. As Appa flies in midair nearby, they look out over the city, toward the ocean and the moon beyond.
In the Fire Nation, Fire Lord Ozai imparts the knowledge of Iroh's treasonous behavior and Zuko's failure to his daughter, Azula, and entrusts her with an special task as she looks up at him, a smile on her face.
- Written by:
- Directed by:
- Also starring:
- Additional voices:
- Dee Bradley Baker
- Mark Hamill - Baboon spirit
- Main article: Transcript:The Siege of the North, Part 2
- Main article: Writing in the World of Avatar
- Main article: Avatar Extras for Book One: Water
- This episode features the second time that Aang has saved Zuko while he is unconscious, the first time being in "The Blue Spirit", when Zuko is knocked out by an arrow.
- This is the second time when Aang meets Hei Bai. The first time was in "Winter Solstice, Part 1: The Spirit World".
- After their Agni Kai in "The Southern Air Temple", Zuko warns Zhao that next time he would not hold back and harm him. However, Zuko offers to help Zhao when he is attacked by La.
- In "The Siege of the North, Part 1", Aang excitedly hopes that the spirits will unleash a "crazy amazing spirit attack" on the Fire Navy. After Aang merges with La, this is exactly what happens.
- When Katara drops to her knees while expressing her sadness over losing Aang, the entire Spirit Oasis island is flipped backward. When facing the pool, as Katara is doing, the characters should also be facing the Royal Palace. In this shot it can be seen behind them. The perspective is flipped 180 degrees to the correct orientation for the next shot.
- When Iroh is talking with Zhao on the boat, the pin on his cloak is a black and red emblem of the Fire Nation, but in the previous episode the pin is gold and red on the same cloak.
- When Hahn tries to kill Zhao and is thrown from the platform, he should have landed on the deck of the ship below, but a splash is heard.
- Koh the Face Stealer claims that Avatar Kuruk tried to kill him "nearly eight or nine hundred years ago". Kuruk died 411 years earlier, meaning that, if Koh's statement were true, Kuruk was at least five hundred or four hundred years old; however, the oldest confirmed age an Avatar has lived is 230, the age of Avatar Kyoshi, at death.
- When Aang is in the Spirit World, he jumps onto Hei Bai's back by airbending; however, it was established in "Winter Solstice, Part 1: The Spirit World" that one cannot bend in the Spirit World.
- When Aang's spirit returns to his body, Katara watches it fly overhead and points to it. However, in "Winter Solstice, Part 1: The Spirit World", in a similar scenario, Katara could not see him, only Iroh could.
- When Zhao puts the fish in the bag, the moon turns red and the sky turns black. However, after the commercial break, the sky was red and the moon was pink.
- After Momo attacks Zhao, he flies to Aang's shoulder. However, as the shot changes to an overview while Aang is explaining how killing the moon spirit would unbalance everyone, Momo is not there. When the scene changes again, Momo is back.
- When Momo is perched on Aang's shoulder as the young airbender explains the consequences of destroying the moon to Zhao, most of Momo's coloring is reversed: his back is black and his belly is white.
- Following the confrontation with Iroh at the Spirit Oasis, Zhao's guards appear and disappear from the Spirit Oasis repeatedly throughout the rest of the episode; the guards appear tied to the left side of the wooden gate, and completely disappear following the spirit monster's rampage.
- When Zhao and Zuko are fighting each other, Zhao eventually takes off his cloak to land right below his feet, but when the screen shows them and the snow on which they are standing, the cloak is completely gone and does not reappear for the rest of the scene.
- The shot of Iroh putting the Moon Spirit back in the pond is the same of him picking it up, but played backward. This is noticeable by the water ripples that disappear when he places Tui in the water. In the following scene, he is still holding it and only then releases it.
- Before Iroh realizes that Yue had been touched and given life by the Moon Spirit, her eyes look as gray as everyone else's, instead of blue.
- Sokka grabs Yue's right hand in order to stop her from giving back the life the Moon Spirit gave to her. However, when a close-up is shown of their intertwined hands, he is holding her left hand.
- When the spirit monster first sends all the Fire Nation ships outward, some can still be seen in the distance, but when the moon reappears, a view of the distant ocean shows no ships at all.
- Aang and the Ocean Spirit's merged form strongly resembles the Nightwalker from Hayao Miyazaki's movie Princess Mononoke. The series' creators have professed their fandom of Hayao Miyazaki in many interviews.
- When the Moon Spirit was killed, everything turned gray, but Yue's eyes remained visibly blue, showing that some of Tui's life was present in her.
- When La and Aang begin moving toward the Fire Navy fleet, the Biblical story of Passover is invoked. When the Water Tribe submitted to La, they were not attacked by him; the Fire Nation soldiers who did not bow were killed.
- This episode is Azula's first appearance outside a flashback in "The Storm" and the opening sequence.
- More spirits appear in this episode than any other. They are the baboon spirit, Koh, Roku, Hei Bai, La, and Tui.
- Near the very end of the episode, Iroh tells Zuko, "A man needs his rest." Iroh also told Zuko this in the first episode and in a flashback showing Iroh and Zuko soon after Zuko's banishment.
- This is the second and last episode where Zhao lashes out after defeat.
- The gate in the Spirit Oasis and the gate in the Spirit World have the same symbol at the top: the symbol for water.
- This episode marks the first time multiple characters are killed; Tui was murdered by Zhao, Yue sacrifices herself to restore Tui's life force and thus become the new incarnation of the moon spirit, and Zhao himself meets his demise while fighting Zuko at the hands of a vengeful La, who dragged him to the Spirit World and imprisoned him for eternity in the Fog of Lost Souls.