Katara and Sokka (a brother and sister from the Southern Water Tribe) discover the Avatar (a 12-year-old Airbender boy named Aang) frozen in an iceberg. Together the three begin their journey to the North Pole to find a master waterbender so Aang can begin his Avatar training!

Aang, along with Katara, Sokka, and their animal friends Appa and Momo, continues on his quest to fulfill his destiny as the Avatar. According to the Avatar cycle, the group must now enter the Earth Kingdom to search for a master earthbender to teach Aang.

Aang wakes up from his battle with Azula to discover that Ba Sing Se has fallen and the world thinks he's dead. So he and his friends set off undercover across the Fire Nation to find Fire Lord Ozai before the Day of Black Sun. Prince Zuko returns home as the triumphant son, but soon finds the honor he so greatly craved from his father is worthless. New alliances are formed and Team Avatar forges a new plan to stop the Fire Lord. But will they find him in time?

In Book One, Avatar Korra—a headstrong, rebellious, feisty young woman who continually challenges and breaks with tradition—sets out on her quest to become a fully realized Avatar, struggling to find balance between tradition and modernity, the bending and non-bending world, and within herself.

In Book Two, the Spirit and Human worlds are colliding and Team Avatar must embark on a journey diving deep into the mythology of the mystical Spirit World, encountering creatures like nothing they've seen before, and discovering the truth about the very first Avatar!

Book Four is set three years after Book Three. Now broken and bruised, Korra begins a journey of self-discovery and survival as the strong prey upon the weak. When an aggressive military force rises up led by the power-hungry Kuvira, the fate of the Earth Kingdom hangs in the balance and only the Avatar can set things right.

Set two weeks after the end of Book Two, Book Three finds Korra discovering that new Airbenders are popping up all over the Earth Kingdom. While she tries to find these Airbenders and rebuild the Air Nation, a group of dangerous criminals embark on a mission of their own.

Avatar Aang, the world's last Airbender, learns of an ancient power that could save his culture from extinction. With the help of his friends, he embarks on a global quest to find it before it falls into the wrong hands and threatens to upend the peace they sacrificed everything to achieve.