I'm looking for a specific fic - I want to save it now. Here's what (I think) I remember...

Pretty sure it's post apocalypse. Cas is basically mortal and on drugs/alcohol and a recluse. People know he's an ex-angel. He's living in a bad part of town and there is a preacher's daughter who keeps trying to get him to come to her father's church cause she sees the good in him. Cas is blackmailed into contacting Dean, possibly by Lucifer or another demon. Dean and Cas are united, but it's uneasy at first. The preacher's daughter pops up later in the story - not in a good way.

Lastly, Dean has a tattoo or talisman that's used to in a ritual, which causes him great pain. Hope this jogs someone's memory. TIA


**FOUND -- info in comments**