Our thoughts and imagination are the only real limits to our possibilities.
Orison Swett Marden
You don't get to agonize over the implications of your secondary character's decision in regard to what will happen to the heroine sixteen chapters from now. You don't get to contemplate the psychology that's driving your hero to act like a madman.
You just write it! Two chapters later, you might not recognize your original story. Hurray! Maybe it's a better story! Maybe your tangent will inspire a completely different book!
Best of all, you don't have to (or get to) worry about it until December 1st.
You just get to savor the possibilities.
Word count: 7489 (I didn't add in the last couple of days individually, like I should. Oh well. :)