Episode Description: Beware, spoilers! To read - hover over the text.
To stop the Apocalypse, Bobby sells his soul. Dean face to face with Death. Crowley tells Bobby that will tell him where there is Death, in exchange for his soul. Knowing Sam and Dean need the fourth ring to stop the Apocalypse, Bobby reluctantly agrees. Sam and Dean are faced with the Plague, but he unleashes upon them a deadly virus, so you have to intervene Castiel.