Avatar: The Last Airbender -- The search

"What hapened to Fire Lord Zuko's mother? Finding a clue at last, Zuko enlists the aid of Team Avatar--and the most unlikely ally of all--to help uncover the biggest secret of his life"--p. [4] of cover, Part 1.

"Avatar Aang travels to the spirit world to parlay with an ancient power, bringing Fire Lord Zuko ever closer to discovering the truth about his mother's fate--and his own past. Yet Zuko's sister Azula is becoming increasingly dangerous, threatening to ruin everything that Zuko, Aang, Katara, and Sokka have struggled to achieve on their search"--Back cover.