Watch anime online, stream anime episodes online for free.Watch Avatar the last airbender Book 1 Water Episode 20 English version online and free episodes. Anime Episode guide, Chapter Avatar the last airbender Book 1 Water Episode 20 he Siege of the North, Part 2 Zuko struggles to find shelter in the freezing temperatures of the North Pole, while Sokka, Katara and Yue search for him and Aang. At the Northern Water Tribe, firebenders and Fire Nation tanks manage to infiltrate the city. Admiral Zhao slays the moon spirit, Tui, and the waterbenders lose their ability to waterbend. In anger, Aang, who along with Zuko was rescued by Sokka, Katara and Yue, goes into the Avatar State and, in joining with the Ocean Spirit Laa, destroys the entire Fire Nation armada and army, with the exceptions of Iroh and Zuko.