Dean and Castiel are trapped in a room together when a monster is out messing with emotions. You don't always need to be psychic to guess what happens next. Destiel

Dean is a demon, and that fact haunts him to the core. Knowing that the hunting life is like poison to him, he quits and gets a house on his own in the middle of no where. One day, an old friend come for a visit, and everything comes full circle, and old feelings begin to surface. (Destiel)

When the Winchesters come across a hunt they can't figure out, they enlist the help from an old friend. Dean's daughter Cassidy is back as the family get in way over their heads. ((see 'Damn Angels' for Cassie introduction))