It has been over eight months since Sweetie Belle accidentally activated an ancient spell. Essentially trapping herself outside of the natural world, causing Rarity to become desperate in her attempts to rescue her younger sister. Since every pony else has failed, Rarity is willing to take her efforts to a level the most would refuse to even consider to save her sister.
No matter the costs.
NOTE- There really isn't any gore (So I felt the tag was unnecessary), but fair warning there a few references to blood and what not...