Plot
A century has passed since the Fire Nation declared war on the other 3 nations of Air, Water and Earth in their attempt to conquer the world. 15-year-old Sokka and his 14-year-old sister Katara, who belong to the Southern Water Tribe, discover an unusual iceberg. Breaking into the iceberg releases a beam of light and reveals a 12-year-old boy named Aang and his flying pet bison named Appa.
Zuko, a disgraced prince of the Fire Nation, detects the light from Aang’s release and arrives at the Southern Water Tribe to demand the villagers hand over “the Avatar”: the only person capable of manipulating, or “bending”, all 4 elements of Air, Water, Earth and Fire. Aang surrenders himself to save the village, but escapes the Fire Nation ship and flies to Appa, brought by Katara and Sokka. The trio travel to the Southern Air Temple, where Aang learns he was in the iceberg for a century and that the Fire Nation wiped out the Air Nomads, including his guardian Monk Gyatso. In despair, Aang enters the Avatar State and finds himself in the Spirit World where he encounters a Dragon Spirit. Katara’s pleas bring Aang out of the Avatar State.
Aang’s group of companions arrive at an Earth Kingdom village controlled by the Fire Nation. When they are arrested and imprisoned, they incite a rebellion, battling and defeating the Fire Nation soldiers occupying the village. Aang tells Katara and Sokka that he only knows airbending and has yet to master the other three elements. They make their way to the Northern Water Tribe where Aang can learn from Water-bending masters.
During a side trip to the Northern Air Temple, Aang is betrayed by a peasant and captured by Fire Nation archers led by Commander Zhao. However, a masked marauder helps Aang escape. Zhao realizes that Zuko is the masked vigilante, and has a crossbowman fire a bolt that knocks Zuko out, but Aang uses his skills to escape with the unconscious Zuko. Aang watches over Zuko until morning, then leaves to reunite with Sokka and Katara. Zhao tries again to kill Zuko, but Zuko secretly survives and sneaks aboard Zhao’s ship.
Upon arriving, Aang and company are welcomed by the citizens of the Northern Water Tribe, and Waterbending Master Pakku teaches Aang and Katara. The Fire Nation arrives and Zhao begins his attack while Zuko continues his independent search for the Avatar. After defeating Katara in battle, Zuko captures Aang, who reenters the Avatar State to search for the Dragon Spirit for help to defeat the Fire Nation. The Dragon Spirit advises him to let his emotions “flow like water”.
Returning to his body, Aang battles Zuko until Katara freezes Zuko in ice, then leaves to join the battle. Iroh and Zhao make their way to a sacred cave where Zhao captures the Moon Spirit. Despite Iroh’s pleas, Zhao kills the Moon Spirit to strip all the waterbenders of their abilities. Enraged by Zhao’s sacrilege, Iroh reveals his mastery of firebending, frightening Zhao and his entourage out of the sacred cave. Princess Yue gives her life to revive the Moon Spirit. Zhao finds out Zuko survived and again attempts to kill him, but Zuko is saved by Iroh and Zhao is drowned by waterbenders. Recalling his life before being trapped in the ice, Aang enters the Avatar State and raises the ocean into a gigantic wall to drive the Fire Nation back.
The Fire Lord learns of the defeat, and tasks his youngest daughter Azula with preventing the Avatar from mastering Earth and Fire.
by:wikipedia