Great drama at D&D this afternoon: The DM revealed that the players had been fighting for the wrong side. The fifth graders were beside themselves with how they were duped by the humans back in the village, who are all cultists. Turns out the guys with tails and fins are the ones trying to stop the Kraken from being resurrected.
Last spring the other DM had all the PCs as acting as undocumented immigrants, having to fight evil while dodging the immigration authorities.
Which makes my middle-school D&D experience even more lame, since there was definitely no greater social context coming into play.