>>96346144
Team Avatar's goal throughout the first season is to reach the Northern Water Tribe at the north pole, to find a waterbending master to teach both Aang and Katara. Aang quickly discovers that in his absence, the Fire Nation has basically been able to take over the world. Only the great walled cities of the Northern Water Tribe and the Earth Kingdom's Ba Sing Se are truly safe from attack, any other settlements are either occupied by the Fire Nation or under constant threat of takeover. They make a bunch of new allies and pick up a new pet: Momo. They're constantly chased by Zuko, and another rival firebender named Zhao. To put it shortly, Zhao is a massive dickbag, but he's an Admiral in the Fire Nation army and has a lot more resources and good standing at his disposal than Zuko. Not to put more pressure on Aang or anything, but he also learns that Sozin's Comet is returning soon, so he needs to kill the current Fire Lord before then.

Everyone reaches the Northern Water Tribe at about the same time. Aang and Katara find a waterbending master, while Sokka falls in love with the Water Princess Yue. Zhao attacks with a fleet of ships, and Zuko sneaks in to capture the Avatar. It's revealed that there's a reason for Zhao's sudden boldness at attacking the Northern Water Tribe: he's discovered a secret weakness. The Moon and Ocean Spirits have taken physical form and reside there, as a pair of fish. If he kills the Moon Fish, he KILLS THE MOON, which will rob all waterbenders of their powers, as the moon was the original waterbender (you know, pulling tides). All Zhao has to do is reach the fish, then his army can take the rest of the settlement.