Part 1: One thousand years ago, an evil Unicorn king of the ancient Crystal Empire was banished from power, but not before casting a spell, causing it to vanish from the face of Equestria. Now in present day, the empire has returned, and Princess Celestia has entrusted in Twilight to seek out a way to protect it. She brings her friends with her to join Shining Armor and Princess Cadance. However, they soon learn that the empire itself is not the only thing that has resurfaced.
Part 2: While supervising the Crystal Fair, Twilight learns that the Crystal Heart is the only thing that can light the spirits of the Crystal Ponies and guarantee the empire's protection. However, King Sombra ('Big' Jim Miller) has hidden the artifact before his banishment. Now with Princess Cadance growing weaker from maintaining a shield spell, Sombra is slowly drawing closer to reclaiming his rule. Twilight must find the artifact before it's too late, but it will take an unlikely ally to bring it to the empi