Avatar: The Last Airbender Season 2 Episode 18 : The Earth King
The group breaks into the Earth King's palace to warn him about the War, which the Dai Li kept hidden. They eventually convince the Earth King by showing him the destroyed Fire Nation drill and Long Feng is arrested for treason. Meanwhile, Zuko succumbs to an illness which Iroh calls a metamorphosis caused by his conflicting destiny and is haunted by nightmares. Azula and her friends, now disguised as the Kyoshi warriors, have infiltrated the city.