Watch Avatar: The Last Airbender Season 1 - Episode 19 - 020 The Siege of the North
The season revolves around the protagonist Aang and his friends Katara and Sokka and their journey to the North Pole to find a Waterbending master to teach Aang and Katara. The Fire Nation is waging a seemingly endless war against the Earth Kingdom and the Water Tribes, Air Nomads. Aang, the current Avatar, must master the four elements (Air, Water, Earth, and Fire) to end the war. Along the way, Aang and his friends are chased by various pursuers: banished Fire Nation Prince Zuko, former General Iroh, and Admiral Zhao of the Fire Navy.