Avater: The Last Airbender Book 2: Earth, Volume 4 contains five episodes and presents the finale of Book 2: Earth.
In Volume 4, Aang, Katara, Sokka and Toph finally find their friend Appa, but their battle has just begun. Princess Azula is close to taking over Ba Sing Se, and Aang and his friends are the only ones with a chance to stop her.
More About Avatar: The Last Airbender:
Avatar: The Last Airbender tells the story of a 12-year-old Airbender boy named Aang (Zach Tyler Eisen), who is a master of all four elements - air, water, earth, and fire. The world is in a state of war since the Fire Nation went on the attack years ago, and Aang may be the only hope for restoring peace to a war-torn world.