The plot bunny has won. Appropriately enough, there was a thread up on the NaNoWriMo forums regarding this exact thing. The thread was called "Bring Out Your Dead!"
Here's my post:
"RIP (Character name removed to preserve the unexpected factor for those I will be forcing this manuscript on):
You were the reliable backbone, the support for my MC as she struggled to maintain a grip on her humanity. Then, well, an evil plot bunny entered the scene and pushed you into saving (Name also removed, see reason above), the guy who was actually supposed to die. My MC was forced to execute you, as one who is bitten by a zombie must be killed, and will now spiral into a bit darker of a place than originally intended. Your death, however, gave me a much needed journey into the softer parts of my MC before she closes them off completely.
Jenn will be getting my hate mail for this character death as well, just to keep the established trend. (Even though I can't actually blame her for this one. Unlike my poor, poor character Tannorth, who had a very happy life ahead of him at one point before Jenn suggested his most brilliant death.)"
My first character is dead. My main character had a slight mental break down. I wrote around 2k words, pushing my total to 27,863.
Today, she'll pick herself off, do some dusting off, and continue on the ever-turning and ever-changing road of plot.