Zuko travels by himself to an Earth Kingdom town were he meets a local boy. The two almost become friends, while Zuko suffers from flashbacks of his past.
Avatar: The Last Airbender 2×07 “Zuko Alone”
https://trakt.tv/shows/avatar-the-last-airbender/seasons/2/episodes/7 (https://www.frederickcalica.com/?p=3344699)