[Man, Sokka kind of hates explaining all this stuff. He's done it so many times now...]

Well, you're already figured out the different worlds from different times all showing up in this place, right? The reason we're here is because of some weird... I dunno that brings us all here. At least, that's what the Malnosso say. They put us in this big bubble land to experiment on us. Apparently these experiments are supposed to help them find a way to get everyone back home.