1. Chapter One: 'The Awakening'
Who convinces Aang to keep his being alive a secret?
From Quiz "Avatar" - Book Three: Fire [1]
Answer:
Avatar Roku
When Aang awakens from a long sleep he finds himself on a Fire Nation ship wrapped in bandages, and though he's initially worried, he soon comes to discover he's amongst friends. The world believes Aang to be dead after the battle in Ba Sing Se, so he and the others are in the unique situation of having the element of surprise.
Zuko, having sided with Azula during the end of the battle in Ba Sing Se, returns home as well to be celebrated by his father, Fire Lord Ozai, for killing the Avatar. Uncle Iroh, considered a traitor, is imprisoned upon their arrival. Zuko keeps it a secret that there's a possibility Aang could have survived.
Though a modified invasion plan is made to take advantage of the upcoming eclipse, Aang decides to go alone, grabbing his glider and taking to the sky to storm the Fire Nation alone. It's then that he's stopped by a vision of Avatar Roku who, with wise words, convinces him to exercise patience. He will redeem him and save the world. As the others find him by morning, he leaves his glider to burn in the fire of a volcano.