King Dainn of the Caribou arrives on the shores of Equestria a consummate exile, with nothing but a loyal crew, a cheap crown, and a grand vision for rebuilding the ruined empire he left behind. His timing is not opportune: a recent economic crisis has deeply shaken the nation's faith in its incumbent ruler, Princess Celestia, and left a large part of the population secretly yearning for a drastic change of leadership.

When Dainn launches his campaign to conquer Equestria and slowly begins to receive support from the disillusioned masses, he sows a seed of discord that grows into a cataclysmic civil war which threatens to strangle the entire nation. Now, it's up to Twilight and her friends to navigate an unfolding maze of political machinations, bloody battles, hidden conspiracies, magic rituals, and ancient prophecies to save their home before there's nothing left to save.