I'm working on a collaboration, as part of a dare on Triggerstreet - and I was fortunate to be paired with a writer who owns a small production company in Spain, and wants to write this as a possible feature for himself to produce.
So far, we've been bouncing back and forth some very general ideas. There is a Japanese myth that I wanted to use as the basis for a screenplay, and which I had some notes, characters, images, scenes developed for... but that idea was an epic fantasy, hardly suitable for a small indie. So, using the same myth (heck no I'm not telling), we looked at setting it in modern-day southern Spain.
I had a trio of characters at the center of my other idea, and I kept those same basic character relationships, but found myself wanting them to be very different other than that. I found a characteristic for the protagonist which lent itself to a good arc, and that told me what I needed from the other two in order for them to push that arc... but I was still lacking something that would make the idea gel.
I was lacking a thematic spine - the idea behind the story, which connects all of the characters and shapes the direction they all go as they come into conflict.
And it just came to me. A single emotional thread which runs through each of the three central characters and motivates them, and defines them. As I did that, more details about the characters, their relationships, and some of the major plot points clicked into place.
Which, again, is so very much like writing a poem. In a poem I might not have characters - but I would have different images or phrases, and it's when I find the common emotional thread that they all come into clear relationship to one another, both in harmony and in contrast.
Ah, that is so satisfying.
Now, assuming my writing partner digs my ideas, we have the basis for a powerful screenplay.