I was on my way to the gym, and something just clicked, and all those bits and pieces of ideas I've been shoving into the backbrain started accreting rapidly: Edwardian England, telepathy, industrialization, Angst, romance, dystopia, war. I didn't read or listen to music the whole time I was on the elliptical because I was worldbuilding and starting to create characters. I went home, fired up the laptop, and cranked out about three paragraphs of synopsis, until my energy started to flag. Then I called C. and begged her to listen. She sounded intrigued. I went back to the synopsis. I'd used up most of my impetus by that point, I think, but I worked until past my bedtime (!) to at least try and bang out a semblance of plot.
Now I have about a thousand words of intriguing setup and a plot that is extremely weak in the details and probably needs to be changed.
It feels great.