I've been trying to find a Spander fanfic recently that I am rather sure exists and its driving me crazy not being able to find it. What I remember is Spike and Xander had recently gotten together, or were atleast new in their relationship, when Spike discovers Xander has some unusual scars on his lower back. The significance of the scars was a message from Angelus to Buffy - I remember there being a mention that it was part of Angelus M.O. when stalking his new obsession; he would cut up the best friend as a message to his 'lover' but the flaw in the plan, this time, was that Xander never told Buffy, or anyone, what happened to him while Angelus was around. So Spike finds out what happened to Xander and he goes and beats Angel up and then the others find out and go beat him up as well.
The name and/or the author would be greatly appreciated!!