HI all. The fic I am so vaguely remembering is extremely dark. Spike is mentally and physically tortured in a cave that goes through a mountain where he is chained up for many years. To the point where he is literally wasting away. I think he's trying to get to Buffy. She's in a hellscape. Maybe actual hell? I think there were blood rivers and dead people. Empty cities etc... I really can't remember. All I know is that this fic had a distinctly different flavor than anything else I've ever read. NC-17.
I might be conflating one or two fics. If anyone can think of anything even a little bit like what I'm describing please don't hesitate to send it my way.