It's happened to me twice now, so I'm convinced that it's not a fluke.
I can now outline my story from beginning to end, and plot a solid, forward moving novel that raises the stakes to a climax. I no longer have to write to discover what I want to do.
Here's what I'm doing: First, I write a general summary of the things that I would like to see happen in the novel. I have some fuzzy moments, and I have to bang my head against the wall, but I capture the entire novel in more or less a sketch. Usually, I think of what the instigators of the plots will do, and I write their actions first. And then, I write the protagonists actions and counteractions. This is a fairly inchoate form, but it generally has forward movement.
Then, I start to write the novel. About a chapter in or so, I go back to the summary, and I look at the thing critically. What moves the story forward? What is slow and needs to be cut? What essential scenes are there that drive the story forward that are needed for tension or the elements of creating tension.
Where the story is slow, can I cut the scene? If it drives the story somehow, what more action-y piece of the story can I pop in there? Do the stakes escalate?
And then I write some more.
Of course, there will be changes. Characters will surprise me. There will be texturing. There will be bits that I hope will work, but won't.
However, I am excited that I spent my writing session today firming up my summary due to this morning's writing epiphany, and then I put the entire skeleton of the novel into Scrivener. This is HUGE for me, a pantser in the past, who usually has to throw away thousands of words.
Don't get me wrong. There will still be lots of work and change and revision. That said, it is so nice to know how to get through the middle of a novel, how to have those benchmarks, how to see the whole picture in the early days.
Actually, this might be the best commercial for Taos Toolbox I could give you.