Prologue

Sam and Dean Winchester are bounty hunters. For a good price, they'll hunt down a wayward vagabond or criminal on occasion. And because they're John Winchester's sons, hunters will pay them to take care of a case or find some magical artifact.

So when two archangels come to them to find a fallen angel, they're only mildly surprised. What does surprise them is the fact that they've been hired to find Castiel, an angel falling from Heaven, and uncover a plot to start the Apocalypse.