After the monstrous Bergens invade Troll Village, Princess Poppy, the happiest Troll ever born, and overly-cautious, curmudgeonly outcast Branch set off on a journey to rescue her friends. Their mission is full of adventure and mishaps, as this mismatched duo try to tolerate each other long enough to get the job done.

Queen Poppy and Branch make a surprising discovery — there are other Troll worlds beyond their own, and their distinct differences create big clashes between these various tribes. When a mysterious threat puts all of the Trolls across the land in danger, Poppy, Branch, and their band of friends must embark on an epic quest to create harmony among the feuding Trolls to unite them against certain doom.

When Branch's brother, Floyd, is kidnapped for his musical talents by a pair of nefarious pop-star villains, Branch and Poppy embark on a harrowing and emotional journey to reunite the other brothers and rescue Floyd from a fate even worse than pop-culture obscurity.