Before Dorothy, before the Wizard, the Land of Oz suffers under the unjust rule of Hastur, the King in Yellow. But when a lost page from the Book of Records surfaces, it reveals the existence of a young boy who is the rightful heir to the throne, and a prophecy foretelling Hastur's downfall. A race against time ensues, with Hastur seeking to avert his predicted fate and maintain control over Oz, whilst Glinda – still just an apprentice witch – strives to escort the young prince to safety. She has her work cut out for her however, as everything from electric dragons to crooked undead magicians stand in her way, and the Yellow King proves himself to be far more cunning than anyone could have imagined.