Plagued with nightmares featuring the devastating power of his Avatar State, Aang and the gang meet an Earth Kingdom general who has big plans for defeating the Fire Nation. Meanwhile Prince Zuko and Uncle Iroh, having survived the failed attack on the North Water Tribe, have a surprise visit from the Prince's sister with seemingly good news.

Despite finding out that Omashu has been captured by the Fire Nation, Aang insists on trying to find King Bumi within Omashu's borders, even with the dangers that will await him and his friends if his real identity is discovered. Meanwhile Azula goes in search of old friends to help her with her mission. Can Aang locate his friend Bumi or will Azula succeed in capturing the avatar?