The mane six have fought Hate and Demise, two of the most powerful creatures ever created. But now they must face their most powerful foe of all. The most powerful of the Whysps Sin, his power was so great that even the great creators of the universe themselves had to sacrifice their own lives to even seal him. When strange things start to happen, the mares become suspicios. They find out they are trapped within their own dreams, how can they fight a threat that they can't see. A better question is how they will escape the dreams Sin has casted them to… find out the answers to this and more in Unholy in Equestria.