Meant to Be by Lauren Morrill
Veronica Mars Season 3
SPN Season 9
Grey's Anatomy Season 10
Until The Wings Unfold | [AO3 Link]
Within the midst of a angelic war disgraced seraph Dean saves hunter Castiel Novak from spending an eternity in Hell. His actions throw the two men into the middle of the war and risk the lives of everyone he and Castiel care about.