Princess Luna disappears from Equestria with hopes of saving the world and is accompanied by the enigmatic Sombra. Meanwhile, Celestia tries to bury secrets as immortal as she is and Cadance must choose her loyalties carefully...
Twilight sets out to learn more of the ways of the world, and soon decides that the whole planet is disorganized, insanely dangerous, and desperately needs to be fixed. And she's just the mare to do it... with a little help from her friends.