-->"If we knew each other back then, do you think we could have been friends too?"

After rescuing Sokka from the storm in the previous episode, "The Blue Spirit" begins with Katara and Sokka both falling ill. Sokka, who started with nothing more than a cough, is now falling into horrible delusions and is barely lucid. Katara attempts to care for him, only to begin coughing herself, prompting Aang to fear for both his friends' lives.

Aang sets off to find medicine from a local healer; however, Zhao has been recently promoted, and wastes no time in using his new clout to send a contingent of elite archers to capture him. Both gathering the cure and evading the archers proves to be too much for Aang, and he is captured. Imprisoned, and with both Katara and Sokka having no idea where he is and being in no condition to save him, Aang finally seems defeated. Suddenly, a ninja in a blue mask appears, frees Aang, and motions for him to follow.

The titular Blue Spirit refuses to speak, but the two manage to escape to the courtyard before being spotted. Despite the Blue Spirit being unable to bend, they fight off guards left, right and center. However, the gates are hurriedly closed before they can make it through, and they are cornered by Zhao and his soldiers. Upon hearing Zhao say Aang must be taken alive, the Blue Spirit quickly brings a sword to Aang's neck, knowing that Zhao can't risk the Avatar's death. Zhao lets them escape- only to have an archer aim an arrow at the Blue Spirit's head.

Seeing the sniper, Aang moves quickly; the arrow hits, knocking the mask off, and revealing the spirit's face. It's Zuko, who freed Aang because he couldn't risk Zhao capturing his only way to return home. Fearful and uncertain, Aang decides that he can't leave the prince to be captured, and takes him away.

Hours later, Zuko awakes in a swamp. Aang sits not far away, talking about how he loved visiting the Fire Nation when he was a kid, and how one of his best friends was from there. He wonders if they could be friends too.

In response, Zuko throws a fire ball at him.

Quickly disappearing, Aang finally returns to Katara and Sokka with the medicine. Despite this and his escape, he seems melancholy.

!!Tropes:
* AbsurdlySharpBlade: The Blue Spirit cuts through the chains and shackles holding Aang with his swords.
* BackToBackBadasses: Aang and the Blue Spirit aka Zuko.
* BadassNormal: The Blue Spirit outfights and outwits quite a few firebenders while freeing Aang, with nothing but his swords and a bucket of water.
** BroughtDownToBadass: The Blue Spirit is actually Zuko, who just isn't using his firebending to avoid revealing his identity.
* BecomingTheMask: Aang hoped that Zuko would have become this. [[SubvertedTrope It didn't quite work that way]].
* ChirpingCrickets: Done with a [[ItMakesSenseInContext defrosting frog]].
* CombatPragmatist: When Aang and the Blue Spirit are cornered, Zhao gives the order to his men to leave the avatar alive. Cue the Blue Spirit immediately holding his swords up to Aang's throat, effectively taking him hostage.
* ContinuityNod: Iroh playing the tsungi horn in front of the jewelled monkey statue, both bought in [[Recap/AvatarTheLastAirbenderTheWaterbendingScroll The Waterbending Scroll]]
* ContrivedCoincidence: Zhao receives word of his promotion to Admiral just as he's trying to recruit the Yu-Yan Archers, allowing him to make his request an order. How lucky can a guy get? Played with though, as there's no established reason why the original commanding officer of the archers should have outranked Zhao. The writers could have given Zhao the authority from the beginning, simply by making the original CO someone lower ranked than Zhao. They created a contrived problem, and moments later presented a contrived solution.
* DescriptionCut:
-->'''Fire Nation Soldier 1:''' Says here that the Avatar can create tornados and run faster than the wind. Pretty amazing.
-->'''Fire Nation Soldier 2:''' Ehh, that's just a bunch of Fire Lord propaganda. There's no way that's true.
-->(''Cut outside view of Aang running past, destroying the lookout'')
* EliteMooks: The Yu Yan archers. They take down ''the Avatar'' with ridiculous ease.
* EnemyMine
* FacePalm: One of Iroh's opponents make this expression when he makes the move that he will win in a game of Pai Sho.
* FindTheCure
* InsultBackfire:
-->'''Aang:''' [[YoureInsane You're insane]], aren't you?
-->'''Herbalist:''' That's ''riiight''.
* SaveTheVillain: Aang rescues an unconscious Zuko from Zhao's soldiers.
* SorryILeftTheBGMOn: The atmospheric background music as Zuko returns to his ship turns out to be Uncle Iroh playing the tsungi horn.
* SplittingTheArrow: While the Yu-Yan Archers are shown at a firing range, one of them splits an arrow, then splits that arrow, and finally the third arrow in succession, so each is embeded in the other.
* TalkingYourWayOut: Aang tries this... unsuccessfully.
-->'''Aang:''' Untie me, and I'll fight you right now!
-->'''Zhao:''' Uh... no.
* ThatsAnOrder: Zhao gets to do this when a messenger hawk arrives just after Colonel Shinu has denied his request to use the Yu Yan Archers.
-->'''Zhao:''' News from Fire Lord Ozai... It appears I've been promoted to Admiral. My request is now an ''order''.
* VillainousRescue: Zuko kidnaps Aang from Zhao.
* WalkingSpoiler: It's next to impossible to refer to the episode or the Blue Spirit himself without mentioning Zuko.