It's all glitter and happiness in Troll Town until Queen Poppy and Branch make a surprising discovery--there are other Troll worlds beyond their own, each defined by a different genre of music. When a mysterious threat puts all the Trolls across the land in danger, Poppy, Branch, and their band of friends must embark on an epic quest through unfamiliar terrain to do the impossible: create harmony among the diverse Trolls to unite them against certain doom.