A while ago I read a great fic (I think it was a WIP verser) about Dean, Cas and Sam being retired from hunting and living together in an ordinary town. Dean has problems with an old leg injury and while working in a bookshop he falls down some stairs and decides he needs a guidedog. Sams's not quite right (after Lucifer?) and frequently forgets where he is, so he wears a laminate with Dean's contact info around his neck. When Dean goes out of town to get the dog, Cas comes and stays with Sam for a while. There were no pairings.

Does anyone know what I'm talking about? I would be so grateful!

ETA: Found in comments, it's the Fusion Verse by ratherastory.