"In the beginning, it's all glitter and happiness in Troll Village 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 do the impossible: create harmony among the diverse Trolls to unite them against certain doom"--Amazon.