Centuries ago, the younger sibling of the Solar Princess was sealed away. What followed that was the disastrous rebellion of the young sister's soldiers. Once the rebellion was crushed along with the Lunar Branch of the diarchy a period of harmony begun... or at least that was what was said. During this period, an "Incident" happened that nearly caused the collapse of the Solar Monarchy. An event that was "lost" to history. Centuries later, after the resealing of Discord; Princess Celestia summoned Twilight Sparkle for a secret mission.

"Twilight Sparkle, please help the Lunar Captain make some friends."

A journey regarding the hidden dark past of Equestria waits for the young hero.