In the war-torn era, An and Ai were pushed to different paths by the hand of fate.They were also imprisoned, but their fates charted completely different trajectories for them.

Aihe was sent to the abyss of the prisoner-of-war labor camp in the Earth Kingdom, where there was endless suffering and torture.An was brought to the king, and surprisingly, the king turned out to be his childhood friend Bumi.Bumi has been mired in the war for the past hundred years, making many difficult decisions that have driven him a little crazy.He regards An as a supernatural being and hopes he can prove his worth.

Meanwhile, Sokka and Katara are determined to save Ann.They learned that there was a tunnel under the palace, but it was unstable and haunted by ghosts.However, in order to save Ann, they decided to take a risk.

In the tunnels, Sokka and Katara encounter a group of bards who enjoy the harmonies of caves.They warn the two that the tunnel is very dangerous and tell them the love story of Oma and Shu.Omar and Shu come from opposite villages, but they fall in love.In order to meet each other, they made a tunnel.However, Oma died in the war between the two villages. Shu used the magic of earth movement to make the two villages surrender and established the city of Oma Shu.This story deeply shocked Sokka and Katara, and made them more determined to rescue Ann.

Elsewhere, Aihe leaves a mark during the transport, recalling his relationship with Zuko.Since he lost his son Luten, Zuko has become his comfort and he regards Zuko as his own son.This flashback allows us to see a warmer side of Zuko.In the end, Zuko successfully rescued Aihe, and the relationship between the two became deeper.

In the final moments, Bumi challenges Ann to a fight to the death in an attempt to prove the Avatar's responsibility.He blames Ann for not being present during the 100 years of Fire Nation conquest, leaving him behind, and leaving Ann feeling bitter.However, at the critical moment, Sokka and Katara appeared in time to prevent any harm.Bumi thinks Ahn is cheating, but Ahn insists that he can rely on his friends' help to save the world, just as he can to win the battle.Bumi is inspired to rejoin the fight against the Fire Nation.

At the same time, Sai revealed the spy group incident to the king of the Earth Kingdom. Inspired by Sean, she decided to join the fight.In this war, Ann, Ai, Sokka, Katara, Zuko, Sai and others united to fight against the conquest of the Fire Nation.Their courage and determination will change the entire battle and fight for peace and justice.