When a little troll discovers his older brother has been captured by two music stars, he embarks on a journey to rescue him. The story recaps the trolls' encounter with the Bergens, monsters who devoured trolls to steal their happiness on the dreaded holiday Troll ssho. After escaping the Bergens, the trolls find a new home in peace. However, when the Bergens attack years later, Princess Poppy's friends are captured. Despite the danger, Poppy decides to rescue them, knowing she won't rest until they're safe from the monsters.