At the Ponyville Schoolhouse, there's a new student! She's a young Unicorn named Lilymoon, and she's...well...different. She never smiles, her cutie mark is a spooky moon on top of a spell book, and she clearly seems to have no interest in making friends with anypony! One day, strange things start happening around the Schoolhouse, and Lilymoon is the prime pony suspect! Can the Cutie Mark Crusaders find out what Lilymoon wants before it's too late?