Chaos reigns over Canterlot as a mysterious unicorn named Dark Secrets arrives to assist the beleaguered Cadence and Shining Armor, who have their hooves full running two empires, searching for Celestia, and trying to deal with the growing shadow spawn attacks. In Ponyville, Twilight has fallen into a depression at the loss of her mentor Celestia, and will not talk to anypony except for Spike and her friends. While time goes on, and Lucid Dream gains strength, an awakened Princess Luna reveals to these ponies a shocking secret, one that asks the question: Is Lucid Dream really the enemy here?