Angels (Supernatural fanfic / Castiel)
Grace Parker is a fallen angel. Way before Castiel came to Dean, back when there biggest problem were demon possessions. Grace got involved with them working on a case. Then Castiel pulled Dean from perdition and he doesn't expect to see another angel with them. Especially one he had a romantic past with. But the past is the past and Grace still has feelings for him but doesn't let that get in the way of forgetting him.