The problem came when I had to think up new stuff. Yeah, my brain-meat loves to kick back with a cold beer and chillax. Sucks for you, Brain! Fortunately, I have an idea of what I want to happen at the end of the book, and I scenes salvaged from the beginning. So when I get down to it, I had two ends of a bridge built up, and then I just had to cross the gap. Again, shuffling cards around came in handy when I had to figure this middle part out. I had a bunch of scenes to work with, but simply had to figure out the best order to put them in.
There's a little more I have yet to do on the plotting. The first draft was one long chunk of text without any chapter breaks. I'm still not entirely sure if I want chapters at all in this book, but I do know that I at least want to divide the plot into sections. If there are chapters within those sections, so be it, but I'm not going to worry about it right now.