In , Zuko and Iroh travel the Earth Kingdom as impoverished refugees, pursued by Azula. After briefly quarreling and parting ways with Iroh, Zuko reunites with his uncle against Azula. After Azula wounds Iroh, Zuko nurses Iroh back to health and Iroh teaches Zuko the rare firebending technique of redirecting lightning. Zuko and Iroh travel to the walled city of Ba Sing Se and find employment at a tea shop in the slums. Zuko reluctantly adapts to his new life until he learns of Aang's presence in Ba Sing Se and attempts to steal Aang's pet bison Appa. However, Iroh convinces Zuko to abandon his quest and let Appa go. Azula infiltrates the city to stage a coup and arranges a trap for Zuko and Iroh. Zuko is imprisoned together with Aang's friend , and the two share a brief moment of compassion before Aang and Iroh come to rescue them. Azula convinces Zuko to betray Iroh, Katara and the Avatar. In the resulting fight, Aang is mortally wounded, though later revived by Katara, and Iroh is arrested for helping Aang and Katara escape from the conquered city.