The Northern Air Temple - S1-E17
Plot hole: They specifically say there is a door no-one but an Airbender can open, but then when it is opened, we learn the Mechanist uses it. How did the Mechanist get in?
Avatar: The Last Airbender (2005)
2 plot holes in season 1 - chronological order
Starring: Dee Bradley Baker, Mae Whitman, Jack De Sena, Zach Tyler
The Southern Air Temple - S1-E3
Other mistake: When the gang is in the Hall of Statues of Past Avatars, Katara points out the avatar cycle pattern of statues and Aang zeroes in on Roku's statue. The earthbender avatar statue next to Roku is of an unknown man with a sword, not Kiyoshi. (00:12:50 - 00:13:35)
The Cave of Two Lovers - S2-E2
Iroh: Where are we going to go? We are enemies of the Earth Kingdom, and fugitives from the Fire Nation.
Zuko: If the Earth Kingdom discovers us, we'll be killed.
Iroh: But if the Fire Nation discovers us, we'll be turned over to Azula.
[Iroh and Zuko give each other a meaningful look.]
Zuko: Earth Kingdom it is.
The Library - S2-E10
Trivia: Wan Shi Tong is of one the few things in this show that is not a reference to Asian cultures, but to Ancient Greece instead. In their mythology owls were the symbol of wisdom and their goddess of wisdom, Athena, was often depicted with an owl.
The Ember Island Players - S3-E17
Question: Is there an inside joke or added meaning to the names that worked on the "play"? The "surprisingly informed cabbage merchant" is obvious, but besides that.
Answer: The pirates are from the episodes "The Waterbending Scroll" and "The Waterbending Master" (They're the ones Katara stole the scroll from). The traveling musicians are from "The Cave of Two Lovers. The prisoners of war likely refer to the Kyoshi Warriors, the men of the Southern Water Tribe, and possibly Bumi and the other citizens of Omashu.