Thanks!  Don't worry, I've got a lot of the backstory planned out; I'm not making it up as I go along (for the most part).  It's just a matter of revealing it within the structure of the narrative, which is difficult, since I'm really tempted to just give all the answers at once.  But if there's something I learned from the TV show, "Lost," it's that sometimes the mystery and the discovery of answers is even better than the narrative itself. ;)