I have searched high and low but I cannot for the life of me find this fic.

It was a long one, at least 20k, and Bobby played a huge part in it. It was also Dean/Cas. I think it only spanned over a few days, in-fic timewise. Dean and Sam found Cas outside their motel, but Cas didn't remember them. He started to slowly regain his memories and there was plenty of confrontations between him and Dean. I think the temporary amnesia was either because he'd fallen or because God had returned.

I'm sorry I can't be more specific, but it was a fantastic fic and I saw it on a rec list somewhere. Hopefully someone will recognize this fic.

Thanks in advance!