Rainbow Dash finds an unusual write it yourself storybook in Twilight's library. Deciding to check it out, she takes it home to give it a whirl. What she wasn't expecting was for the book to be enchanted, bringing her to a new world.
During the Invasion of Canterlot, Chrysalys uses an ancient changeling ritual to cast Celestia from reality itself. She ends up in another world entirely, and her adventures within it bring not only questions, but answers as well.
Sasuke and Naruto defeat Madara and the Juubi together, but are betrayed and thrown into time and space. Ending up in Equestria, their presence brings forth unforseen consequences.