Ballance Between "episodes" and "orgainc" Stories

HurstGM

OK so I have a new game and its taking off well. No stumbling blocks ect. I have some AWESOME stories lined up for it and am making NPC's ect. for it. Now the thing i see coming down the road where I want an organiclly grown story and world, but Im trying to enter these "episode" stories. Anyone have any advice on how to balance this or the pitfalls i might run into?

AugustusGloop

I read an idea a while ago about compiling a secrets book, which is a list of at least one secret fact for every minorly/very important person, place and thing in your world (even the ones you made up on the spot because the pc's did something unexpected.) Then when you're playing, you can leak secrets slowly about the things they're interacting with, and pay attention to the ones they're really interested in. Then, in a later "episode" you can explore the interesting revealed secrets one by one, and make your players think you had the whole campaign planned out from the beginning. If you do it right, you can bring about some seriously epic player (inadvertently) created stuff.