Aang and Katara arrive in Yu Dao with the mission of warning Fire Nation citizens of the Earth King’s plan to attack. However, they are attacked by a strange mixture of firebending, earthbending, and physical weapons. They discover that the attackers are Sneers (a member of the Freedom Fighters), Kori, and some earthbenders, calling themselves the Yu Dao Resistance. 

The Yu Dao Resistance insists that the Fire Nation citizens should not be forced to leave the city because they are beloved community members: family members, teachers, local business owners, and more. When Aang tells them that the Earth King is sending an army, Kori retorts that the Earth King could be defeated with the help of the Avatar. However, Aang is hesitant to join their cause because he has already committed to helping the Harmony Restoration Movement.

In the middle of their discussion, the Yu Dao Chapter of the Avatar Aang Fan Club arrives, offering to help Aang defend the city. Aang is offended when he sees that they have adopted Air monk robes and tattoos, telling them that his culture is not a costume they put on. Aang declares that the four nations need to be separated for good and storms out of the room. Meanwhile, in the Fire Nation Palace, Zuko considers reaching out to Iroh for advice but decides against disturbing his uncle’s new, peaceful life.

Aang forlornly sits on Yu Dao’s outer wall, waiting for the armies or the Freedom Fighters to arrive. Katara asks him what is wrong, and he expresses his fear that intermingling between the nations will inevitably lead to the destruction of the weaker cultures. He is worried about preserving his own Air Nomad culture, endangered after the Fire Lord Sozin’s genocidal campaign, in a multicultural environment. Katara wonders if killing Zuko to ensure the separation of the four distinct cultures isn’t inherently opposed to the air monks’ nonviolent teachings. Aang acknowledges this contradiction, saying that it makes his head hurt.

Suki arrives at Toph’s metalbending academy in a war balloon to pick up Toph and Sokka. She tells them she needs their help to deal with the upcoming conflict. Below, they see Zuko’s army marching toward Yu Dao. Meanwhile, the Freedom Fighters arrive at the outer wall, interrupting Aang and Katara’s conversation. They attack the wall, and Aang tries to stop them. Then he realizes that they were distracting him from another group that was drilling through the wall. Toph and Sokka begin disabling Fire Nation tanks on the ground to weaken Zuko’s army and prevent unnecessary violence. Smellerbee and the Freedom Fighters make it inside Yu Dao using their drill.

Smellerbee is angry that Sneers would abandon the Freedom Fighters for Kori, a firebender. Sneers tell Smellerbee that Yu Dao might not just belong to the Earth Kingdom or the Fire Nation anymore. Fighting breaks out, and Aang begins to worry that a peaceful solution might not be possible. At the same moment, the Earth Army arrives.

As the scene outside Yu Dao becomes increasingly chaotic, Katara pulls Aang aside and tells him she wants to finish their earlier discussion. She says that the Morishitas’ blended Earth and Fire Nation family reminded her of the future she imagines with him. She worries about what separating the four nations entirely would mean for their relationship. She encourages Aang to take some time to consider. He earthbends a small enclosure for himself and begins to meditate.

In his spirit form, Aang converses with Avatar Roku. Roku tells him to fulfill the promise made to Zuko and ensure global harmony. Aang says that doing so would be a rejection of the Air Nomad philosophy and an act of violence against someone he loves. Roku reminds Aang that the Avatar must always prioritize the world’s well-being over the well-being of his loved ones. He remarks, “I cannot put into words how much it pains me to advocate for the end of my own great-grandson” (200). Aang had not previously known that Roku was Ursa’s grandfather and is horrified that Roku would ask him to kill his own family member. Roku ends the conversation by telling Aang to focus on the world’s well-being.

At the battle, Toph, Suki, Katara, and Sokka join the action. Toph and Suki work together to disarm Fire Nation soldiers with the help of the metalbending students, while Sokka breaks up a fight between Smellerbee, Sneers, and Kori. Meanwhile, Katara identifies the war balloon where the Earth King is overseeing the action. She waterbends her way up to it and inside, finds Kuei cowering, terrified by the battle. She tells him that he needs to get on the ground and meet the people who are affected by his decisions. Zuko enters the fighting just as one of the Earth Army’s generals begins to try to arrest Fire Nation citizens.

At the same moment, Aang breaks through his rock fortress in the avatar state and splits the ground between the two sides of the fighting. Zuko realizes that he is doing exactly what Ozai would do. As the earth splits open, he falls into the void. Aang zooms toward him and grabs him by the wrist, pulling him to safety.

Katara brings the Earth King to where Aang has landed with Zuko. Aang tells Kuei to look at the multicultural gathering of people he is fighting, telling him, “You’re not just fighting a colony, you’re fighting a whole new kind of world” (215). Kuei says he needs to go into the city and see for himself. Zuko collapses in exhaustion.

In another spirit form conversation with Roku, Aang tells him that he considered the world and realized it is made up of all the people he loves, Zuko included. Roku says that sparing Zuko endangers the world, but Aang believes that there is no way to avoid this danger in the new multicultural world. He tells Roku that there are new problems that he needs to solve on his own and permanently severs his connection with Roku by destroying the fire amulet that facilitated it.

Inside Iroh’s tea shop, Zuko has woken up and is healing. Iroh says that Zuko should have come to him for advice. Zuko and Aang talk about their shared dream, and Zuko apologizes to Aang for pressuring him to make the promise. Zuko mentions that Ursa appeared in their dream, and Iroh remarks that dreams can contain the answers to people’s problems. Zuko begins to think that finding Ursa might be possible and summons his imprisoned sister, Azula, to help him. Aang begins to teach Air Nomad philosophy and culture to his fan club, which he renames the Air Acolytes.