Pinkie has a secret. So far, she's kept it from everyone, but Twilight can tell that something's wrong with her. So she offers what vague support she can… until Pinkie takes her into the basement to show her.
A long-history era of history is revealed, old allies are called upon, and a fallen king is rising. And it all started with the death of a single pony.
When Sweetie Belle and the other Cutie Mark Crusaders explore the Castle of the Two Sisters, she comes across a strange artifact that sets into motion events that could change her life.