How far did you get so far?
I've got a very satisfying 5654 words now, and also spend time working out my timeline (with Aeon) which helped a lot. It also helps that I made the outline before I started writing and that I decided to fall back on a technique I used as a teenager.
Basically:
"Write down whatever scene you have in your head!"
As a teenager I used to write in a scattered way. Whatever scene I'd come up with, I'd write. At times I felt more like writing the story chronologically (well, in the order that it happened in the story) and whenever I'd get to a scene I'd already written I'd either just toss it in or did some rewriting of it (a second draft) right then and there. For some reason later on I thought I had to write in a linear way...
Yesterday and today though, I haven't. I have scraps of scenes, and some full scenes. I have a start and have written my two most important flashbacks way before the scenes surrounding the flashback (and I like that, I've found that I semi-refer to the events more in the other scenes now that I've worked out the flashbacks. It adds more depth.) My brain bounces from left to right and up and down.
In short, so far so good

But I do need more sleep

Tanja