Spike makes a deal with Ethan to get his chip removed.

Hi guys. I've been trying to remember the title and author of a fic in which Spike makes a deal with Ethan to get his chip removed. He knocks Xander out and is about to bite Willow but she begs him not to turn her or hurt Xander and he can't go through with it. He takes off to new Orleans and the ghost of a long dead slayer who had loved a vamp ends up tagging along with him. Someone kills a little girl, I think and leaves the body in Buffy's yard in an attempt to frame Spike. Buffy's hurt cuz she didn't believe he would do such a thing. Anyone remember what fic this was?

That's "Adversaries" by Miranda. not sure where it is online but I have a copy - if you pm me I'll send it

I found a link:

Adversaries by Miranda

BtVS Season Five (after Checkpoint, then AU after that.)
Rec: Delylah says: This is a 14 part Buffy/Spike fiction about a prophecy concerning the Slayer uniting with her vampire Adversary that I very much enjoyed. I found the Buffy/Spike angle and characterization very convincing

That's the one. Thanks tazandhooch and 0hallie0. It's been driving me crazy.