Animal, Vegetable, or Mineral?

I don't know what I'm writing.  But I am writing, it is pouring out of me, I can't seem to stop it, it just keeps flowing though I have no idea what it is.  Is it back story for a play?  A short story?  A TV show pilot?  A short film?  Or, if it keeps going like this, something longer?

A little background:  I am currently enrolled in a "short forms" class at ESPA, the Primary Stages theater school, with Sheri Wilner.  Sheri gave us a "subtext" exercise a few weeks ago, where each character in the scene had to have a secret.  She gave a list of possible secrets, one of which was very serious, the other was very silly.  I decided to challenge myself and pick two of the silly/absurd secrets, in the hopes of writing something out of my usual family-drama milieu.  After a couple of attempts - and some great input/advice from Sheri - I managed a scene that I actually felt pretty good about.  I knew it needed work, it needed to be deeper, but it was a start of something potentially interesting.

Then last week Sheri gave us another exercise, to help us discover the themes of our plays.  We had to first identify the questions our play is asking, then draw parallels between these questions and our own personal lives.  At first I thought I couldn't possibly apply this exercise to this silly little fantasy play, I would be better off picking the family drama piece I had written the week before.  But then I decided to keep stretching myself and just do it.  After all, isn't fantasy/sci-fi good when it is based on something very real, so we can look at it in this completely different context?  Lo and behold, I discovered that my play was indeed asking a very strong, real-life question that has complete relevance to my life, that is in fact one of the struggles that has been a constant one for me from a very young age.   I even got a little teary about it, all over this "silly" little play.

So I began to write about the character and what this question means to her.   Suddenly pages and pages - 6 full pages of single-spaced prose so far - of back story began to flow out.   I can't stop - I find myself delving deeper and deeper into her, writing details upon details about events that happen many months before my play is set to begin.  I feel like I am writing a book or a movie or I don't know what, but she is so alive in my mind and her experiences -- though completely fantastical -- are very visceral and real to me.

I don't know if I should (there is that word I try not to let myself use) stop writing this back story and get to the play, or just let it keep flowing and see where it goes.  It seems silly to stop a process that is so clearly having abundant creative flow - but I would eventually like to get to the actual writing of the play!  I think, though, that I have to work out the steps that brought her to the moment of the play -  a very intense life or death moment, despite the fantastical trappings of it - to really know where she is in that moment. I think then the scene may well write itself.

So back I go to writing this surprise tome -- this woman's history which probably no one will ever read or see, unless I suddenly turn into a fantasy fiction writer.... (as if I need another distraction...)