I could be mixing up a couple fics? But these are the things I remember.
1. There was a trial, possibly involving Xander's father, in which Spike surprises Xander by having false identity papers that allow him to testify?
2. They live in a big house/mansion somewhere by the end of the fic (but not always throughout the fic). I think Spike buys this mansion for Xander?
3. Willow feels guilty about something, I can't remember what, and comes up with a way to bind Spike and Xander together so that they can be together until they both die (letting Xander live until Spike dies, basically). She kind of gets obsessive about it, not eating/sleeping, until she finds the right spell.
Also, I am looking for the old classic that I'm pretty sure is a separate fic (but may be the same one as above, I don't know!!) where Xander fixes Spike's chip by using a giant magnet on one of his construction sites?
