In the aftermath of the Devil rising, Sam and Dean are whisked away and they are given a message from Chuck Shurley that Castiel is dead and that Luficer walks the Earth. As a result, Sam and Dean turn to Bobby for help to find a mystical weapon, called Michael's Sword. This will enable them to find the Devil before he takes on a new form to bring the slow end of the world. But the Winchester brothers are pitted against the archangel Zachariah who has plans for Dean, as well as more demons. Sam and Dean recognise a demon, Meg, who has returned from Hell.