This is such a difficult question to answer, and I’m learning my own response to it!
I re-wrote Regression a number of times, and actually am going to work on an omnibus for the holiday season which includes the first draft (alternate ending) as a bonus. Interestingly enough, neither Evolussion nor Revolussion have alternate endings since the first draft was very close to the completed copy. Why?
Because I learnt that the book will never be finished until I choose it to be finished, because there is always something which could be changed. When I read Regression, I begin to re-write it in my head, while I am more satisfied with the other manuscripts.
So the completion of a manuscript is the point at which you the author think it is finished telling the story. In looking at Revolussion, I know there are the smaller, side story-lines which I could have kept on writing, but I decided that those could be left up to the reader’s imagination. Dawn’s story was over. At least, her story as the mother of humanity. Stew, Nicholas, Hope, Avery…I could continue with their stories, but their roles in the original plot have ended, and I need to take a break from the Infinion Series to test myself against new material. Can I write something else? Fantasy? Science Fiction? Contemporary? I want to try them. And then, I might come back and carry on where Revolussion left off!
Look for news on Synergy 2012: Return to Magic on the blog as I begin a new project!