This is actually a pretty strange episode. It does not tell the viewers a lot, and it doesn't have too much good action. Indeed, it's composed of a lot of filler to stretch the twenty-some minutes of each episode. Which would then make this chapter pretty bad, were it not for the significance of those few important bits that were placed into this episode.
The first thing we get is Zuko and Iroh living as beggars. Other than this introduction, the only other thing that is shown is all the way at the end, where Zuko once again assumes his alter ego of the Blue Spirit. This development, even though it takes up so little time, is pretty much just as significant as all the stuff happening to the gang.
The rest of this episode deals with the gang finding their way around in a gigantic swamp. Right from where they land in the swamp, the pacing is weak, and the whole episode seems very sluggish. This state doesn't really improve that much, and only the fight scene is a bit of a reprieve.
The first thing that went through my mind when Aang sees the girl was the Tomb Raider movie, where Lara Croft chases after a girl in Angkor Wat. The mysterious chime-like music in the background also fits. And though we don't know yet who the girl is, we're bound to find out soon. It's sort of a mix of whetting the audience's appetite and preparing the plot for what is to come.
We also get some nice, albeit ungrounded, philosophy about how everything in the world is connected. I guess the most important bit of info revealed here is, again, that Aang will meet that mysterious girl from his vision.
Appa's and Momo's plot, while quite funny, is simply not as engaging as the gang's part of events. We get them trying to fight their way through the swamp, and then the show introduces hillbillies. After anime pirates and hippies, I guess the creators had to put on yet another trump, and get some stereotypical social group into the show. Not that I mind, it doesn't really disrupt anything (hillbillies in a swamp is much more rational than some strange Asian folk that doesn't actually exist), and it adds to the humor.
The story ends with the gang sitting together with the swamp people. It is interesting to note that next to the Tribes at the poles, there's also waterbenders who live in the great swamp. It adds more color to the world, and makes the distribution of benders in society less strict and static. Plus, these guys can bend water in plants, whereas, probably in exchange, the polar benders can freeze and melt water. How the swamp dwellers would have any idea what ice and snow is, however, is beyond me, but it's a good joke.
This episode is not bad, it really isn't. But it's a bit empty. Yes, it thrusts the gang into a strange terrain, and it reveals things both from the past and for the future, but it's not much. And the thing that pulls the grade down the most is Sokka's constant bickering about the swamp being just a regular swamp. After all the spirituality and mystical things he's experienced - he did get dragged off into the Spirit World - his attitude was just off. It would perhaps have been fine if he didn't mention it every two lines. For me, the episode as a whole suffers greatly from it, something that didn't have to be.