The creators of the show call each a "book" and each episode a "chapter"; each of these books was take the name of element that Aang must control, except the air. Flashbacks also reveal events that happened before the show opened. In a flashback during "The Storm", Aang remembered the day when elder monks told him that he was the Avatar. Monk Gyatso, Aang's teacher and father-figure, said that Aang must be raised as a normal child. Nearing the end, the monks began to believe that Gyatso interfered too much, so they decide to send Aang to the Eastern Air Temple. Aang refuses to be torn away from his mentor; he writes a note for Gyatso before flying away on his bison, Appa. It is revealed in the first episodes of the show that a violent storm catches Aang and sends him into the ocean during his escape. Aang then enters the Avatar State, unknowingly, for the first time to encase himself and Appa in a frozen air bubble. An image of this air bubble, resembling an iceberg, ends the flashback.