Following the events of Fires of Friendship and Ice of Hatred, Midnight Sparkle has escaped to another universe entirely, Burning Star's allies Quickfire and Hiller are sent to capture her, and have to team up with group of elite ponies for help!
The Mane Six are joined by three others in a quest to use the Elements of Harmony one last time, as a brewing war between Tartarus and the free creatures of the world threatens to destroy Equestria forever.