The End of Dead End

How do other writers manage to finish a book? How do you? The first in my series, CUT SHORT, wasn't planned in advance - I simply ran with an idea. Before writing the second in the series, ROAD CLOSED, I did a detailed plan and went further with DEAD END which is coming out in 2011, and wrote a ten page synopsis before writing the first draft. I have done the same for the fourth in my series. Now, with all 64 chapters written, the first draft of the fourth book is complete. It just needs a little polishing before it goes off to my agent. I know what to do and could easily finish it in a couple of evenings. So what's the problem? It can't be described as 'writer's block' (whatever that is) because I know exactly what to do. But once it's finished - that's it. So what is stopping me? Why is it so hard to let go? After months researching and and enjoying writing my current MS I just don't want this to stop. If I wasn't writing a series I would never reach the end of this book... it's a struggle as it is, at least until an idea for what is going to happen to Geraldine Steel in the fifth book starts buzzing about in my brain...
Leigh Russell