Muted Angels

Alternative Reality, non-supernatural. There's nothing worse than a case involving dead kids, at least in the book of Detective Dean Winchester. It's just his luck that his partner is the lieutenant's favorite, and she chooses to give them the high-profile murder case of a dead girl from the suburbs. More deaths follow, and the two of them get sucked into the world of religious cults and ritualistic murders. In the face of that, Dean's feelings for aforementioned partner are the least of his problems.