I know that this one has been requested before, but new computer = lost links. And I can't remember title or author ( of course) so here's the gist of it. The one with Isis. She is trapped in the form of a snake and Xander takes care of her. There's also a reappearance of Angelus, Angel's involved with Doyle, and Drusilla is there as well. Also Graham becomes obsessed with Xander and stalks him, has a little shrine to him etc., etc. and super creepy.
Like I said, I know that this one has been searched for a few times, and I apologize, but I just can't find it.