Avatar: The Last Airbender Season 1 Episode 8 : Winter Solstice: Avatar Roku (2)
Aang has to travel to the Fire Temple to receive the message from Avatar Roku on the Winter Solstice. They are chased by Zuko and attacked by a Fire Nation blockade led by Zhao on the way there. When Aang gets to the temple he is shocked to learn the five Fire Sages there are no longer the Avatar's allies. However, a friendly sage helps Aang get to the sanctuary where he can talk to Roku. Avatar Roku informs Aang about "Sozin's Comet," which will return in just under a year and give the Fire Nation the power to finish the war. When Aang leaves the sanctuary, he is attacked by Zhao and the Sages. Aang defeats them when he manifests the spirit of Roku, who destroys the temple.