Twilight Sparkle is called away to tend to Luna when she falls ill. As Luna grows sicker and Twilight more determined to help the younger princess, she begins to uncover dark secrets about the elements, the alicorns, and her own past.
Five years ago, The Rainbow Factory was condemned by Princess Celestia and many questions were left unanswered as to why. Now, as a filly, starting your first year in flight school, your classmates decided to give you a test to prove your worth.