The Everfree Forest, a mythical place surrounded by campfire ghost stories and plagued with rumors of evil. Mostly, all of this is attributed to the strange workings of the Forest, how it seems to run itself. It's never been natural. But lately, rumors have been spreading of an eerie fog that is seeping from the woods. Twilight, naturally interested in such a strange development, sends a letter to the Princess seeking assistance in investigating. Almost immediately, she is replied to.

The only words on the letter, "Urgent. Meet me."

Somewhere in the Forest, a evil awakens, one that hasn't plagued the world for a millennium. One so fierce, even the Princesses fear there is no hope.