Help!
Any ideas?
I write historical fantasy. I know precisely where I need to go with the story, and I'm excited to get there... I just... can't. None of my usual tricks are working.
Your mind doesn't have tracks to run on yet.
You might have to ask yourself the right questions to figure out where you have to go to get from where you are to where you know it has to be, and then you'll have a framework and the words will come because you have something to describe.
Develop the plot first, then write it. And of course character determines plot.
So you can move from the known to the necessary, and between character and plot.
In other words, you think, I know where the story is now, and I know where it's going to end up at a certain point, so if both of those things are true, what must happen in the meantime?
Once you've figured out, generally, what you think happened to get there, ask what impact that would have on the characters and how they'd react.
If the characters are well devloped, sometimes they react in ways that don't get you from A to B, so you have to decide to change B (where you thought the story was going) or to go back and think of another way from A to B that doesn't elicit that reaction in the character.
Once you do figure out why the characters move from plot-point A to plot-point B, then you have a new set of questions to ask: What does all this new information do to the characters?
When you answer that, suddenly you have ideas for where the plot moves next. (Or maybe you have to change stuff you wrote before.)
In short: Move back and forth asking "What do I know?" and then "What does that imply for the plot... what should also be true?" and once you've answered that, then "What affect does this new plot information have on the characters?"
Then you ask, "Ok, so I know something new about the characters... what would these people do in the new plot situation I've put them in?"
It's a method that you can take as far as you want.