***SPOILER***
It starts out with the end of "The Day of Black Sun: Part Two, The Eclipse" with Zuko following them through the hot air balloowen. Then it is cut to a clip from "The Western Air Temple" where Zuko offers to be his teacher. Then it shows the part from "The Firebending Masters" where Zuko and Aang dance with the dragons. Then it shows some weird clip of Aang and Zuko doing the Dancing Dragon outside of some building (I assume this is from the Boiling Rock) Then Aang is kissing Katara, and Katara pulls away. (I assume this is from "The Ember Island Players" or the finale.) Then it is cut to Katara hugging Zuko under the sunset. (Good news for Zutara fans, this will get their hopes up. This should be from the Southern Raiders). Then it goes back to the clip from "The Firebending Masters" where Zuko and Aang watch the colors of the dragon fire fly by them. Then it shows Aang meditating behind some candles. (Problably from the finale, or the night before the final battle). (In the backround Zuko is talking about the comet). Then it shows Ozai walking up to the camera, and then it is directly cut to a giant flashing meteor or something slicing through rocks (I assume this is the comet). Then Aang is jumping off a cliff with his glider (the only thing I don't understand about that is that I thought he lost his glider again in 313). Then it is cut to Katara bending water out of some grass. Zuko is behind her, and some old man/women is laying down in front of them. The trailer is cut to Zuko jumping on to Appa and Katara catching him. Then it is cut to June (the bounty hunter from 115) fighting some old lady/man with a croud watching. (This should be in the finale). Then it is cut to Azula and Ty Lee fighting. (Most likely in the finale). Then Azula is caught (or controling) orange colored fired. (this might be the death of Azula). For sure from the finale. Then Zuko is saving Sokka off a wiggling roof of something. (From finale I guarentee). Then the screen is cut to Azula running towards a fire army soldier and tripping him. (From finale) Then a close-up of Katara's face turns up, and her hand comes in front of her eyes, problably preparing to bend. Then Aang and momo are standing on a cliff in front a giant lava flood. (Most Likely Ozai's power). Then it shows two people (most likely Zuko and Katara) crossing a river with something that looks like an ice surf-board thingy. Then it is cut to Suki and Sokka, and then Toph quickly bends them up and away from something. Then Azula is attacking someone (don't know who because of the shadows in the video). Then Aang airbends at the camera with a giant wall of fire behind him. Then (maybe Zuko) jumps over a huge hole seperating a machine from another peice of land. Then Appa is shown dodgeing a bunch of fire bombs. Then Azula is shown again standing in front of a wall of blue flames. Then Katara jumps down onto a red dragon, ready to strike an attack. Then Aang is shown airbending at someone, but before we see who it is he is shooting at, it is cut to Zuko or Azula doing something with blue flames. (Either Azula bending or Zuke Re-Directing). Then Aang is attacking someone by jumping on top of someone unknown. Then Katara is shown bending water at someone, but like before, we don't see who she is attacking. It is cut to a hand in front of the screen reaching up to Sokka. (Toph falling off a building and Sokka helping her up.) Then Azula is being firebended at, and she blocks it. Then Aang is shown creating a giant wall of earth, and then a giant wave of fire hits the wall. Then Zuko and Katara are shown in a fighting drill destroying rocks shaped like firebenders. Then may is shown getting ready to attack someone. Then there is a small clip from Zuko in "The Firebending Masters" again. Then Aang is shown throwing a HUGE flame of fire, and aiming it at someone. (Aparently Ozai). Then Appa is shown in the air with a tight turn so that Zuko falls off. Then Sokka is shown guiding Toph through some weird place. Then Ozai is shown being crowned the Phoenix Lord (I think, [this might be false]). Then either the comet or a giant wave of fire is seen slicing through a fire-red sky. And then, Aang is shown under the sunset, looking down. (I think that might be the last scene of avatar, when he has killed Ozai). And then lastly, Sokka is shown with his hair all messy and a stick in his mouth.
WOW. Now discuss what you think of all the info I picked out here.