The season takes place largely in the Earth Kingdom, one of the four major nations in the setting of the series, and also depicts the re-emergence of airbending among people of other nations. The season's antagonists are the "Red Lotus", a group of dangerous anarchists led by the new airbender Zaheer who wants to overthrow the world's governments and the Avatar. Among the season's new supporting characters are the now elderly Zuko, a character from the original series, as well as Lin Beifong's sister Suyin and her family.