The first decision I have to make is whether to use the 10,000 or so words I already have and add to them. That wouldn't just be a case of continuing the story; I have extra scenes I need to add at all points so that the characters' actions make more sense in context, and possibly so that more points of view are reflected.
For Once An Assassin, which I recently finished (although it needs some editing before I think about submitting it anywhere), I took the basic plot and main characters from an old fanzine story. I used the first line from the old story, and some of the first scene was similar, but after that I pretty much wrote it over again. Partly that was because of the nature of the rewrite. I had to change the story of one woman's journey, set against the backdrop of events in other people's creation, to a romance of sorts. I had to convert an antihero into a flawed hero, and I had to give the pair of them a Happy Ever After (or at least a Happy For Now).
My heroine's journey was very similar in the various versions, although for the newer, longer version I had more opportunities to delve into her background, her thought processes and her reactions to what was happening to the hero. For the hero, I gave him a family by birth, a family by marriage, and a support network of comrades. This allowed me to make his first escape from death into a planned event, rather than something that happened by chance. After that it was more believable that he might have survived subsequent with the possibility of eventually being reunited with the heroine.
For my YA story, I'm probably going to keep the first scene and then write a bridging scene into the main body of the story. This may mean I have to ditch or heavily rewrite subsequent scenes in order to keep the flow going. My picowrimo target is therefore going to start at the length of that first scene plus 6,000 words. Any other scenes I reuse will add to both the word count and the target, as my aim in the challenge is to write 6,000 new words, no matter how many I reuse.
The overall plot will remain the same, and I still hope to use some of the scene ideas I came up with, but never wrote, the first time around. It will be interesting to see how much of a story I have at the end of the month.
I think I'll write more on this topic next week. My visitors have made me post late as it is, and I have at least another post's worth of thoughts and examples.
How about you? Which is easier: heavily editing an existing story or writing the same story all over again from scratch?