So here's what I remember:
Spike has loud and vivid nightmares (either cause of his soul or the chip can't remember). He's staying with Xander and he can hear them. If I remember correctly Spike's not eating or is extremely weak. Xander takes him to Angel for help and does something...some ritual or something to get Angel to help Spike. I believe offered blood or submitted or something. He has the knowledge from Giles books.
This fic is this niggling thought in the back of my mind and it's driving me crazy cause I can't remember when I read it last and I can't find it in my bookmarks.
Please, anyone, help?