A distant civilization of ponies, removed from Equus millennia ago, send an expedition to their ancestral home to solve the mystery of its strange orbit. They bring a foreign mindset and powerful, conflicting interests to the peaceful world.
As a joke during his original rule, Discord sent a group of ponies to a distant, inhospitable planet and left them alone. Thousands of years later, their descendants notice a star in their sky orbiting inexplicably around its planet.
In the wake of Tirek's return, the Equestrian nobility faces the reality that the nation's security hinges on the power of six mares. They charter a secret organization to defend Equestria from that which threatens it, by any means necessary.