Pearl Prose is an average filly, living with her director mother and her writing father in a penthouse apartment in Manehatten. One day in a Carrie-style streak of unicorn magic, she winds up with wings! Whisked away to a life of a Canterlot private student of Princess Celestia. Locked in a tower, her only friend is a mysterious pony who sends her letters every night, comforting her. Who is this mysterious pony? And why does he wear a mask.?