When the young alicorn, Twilight Sparkle discovers what she truly means to her former teacher as well as her subjects, she is so overwhelmed by it that she needs to get away for a day. Like she had done so many times before her ascension to alicorn-hood, Twilight escaped her problems by returning to the abandoned Castle of the Two Sisters to, once again, explore it's mysterious depths.

But what happens when she discovers a secret her loyalty to Celestia has kept her from finding? Deep in the abandoned castle is one, single tomb that will alter the way Twilight and Celestia view each other forever.

Twilight will prove her worth to the princess of the sun yet again. Though not in a way she might have thought.