As the Summer Sun Celebration approaches, Princess Celestia sends the young Guard Lieutenant Twilight Sparkle to Ponyville to make final security and preparation checks. In Canterlot the Princess's Apprentice, Shining Armor, works to uncover the hints of an anarchist movement striking at the City's heart. When Night falls the young Princess Cadance is left trying to hold the heart of Equestria together in her aunt's absence