An infant Branch and his four older brothers John Dory, Spruce, Clay and Floyd perform as a boyband called BroZone. When their clashing egos prevent them from performing the "Perfect Family Harmony", a powerful ability that Trolls can achieve when they are in complete sync, the brothers argue and break up the band. Branch is left alone to be raised by his grandmother Rosiepuff.In present day, about a month after preventing the Rockpocalypse, Branch and Poppy attend Bridget and Gristle's wedding in Bergen Town. They are interrupted by John Dory, who reveals that Branch's closest brother Floyd has been captured by Velvet and Veneer, two Mount Rageon teenagers who wish to be pop stars. The siblings have imprisoned Floyd in a diamond perfume bottle, which they use to extract his essence and improve their singing, although the process could eventually kill him. As the Perfect Family Harmony is the only thing that can destroy diamond, Branch reluctantly agrees to help John Dory find their brothers and rescue Floyd. Along with Poppy and Tiny Diamond, they set out in John Dory's armadillo-like portable van named Rhonda.They find Spruce at the Vacay Island resort, where he has changed his name to Bruce and started a family. Bruce is reluctant to help, until his wife and 13 kids convince him to do so. The group later finds Clay at an abandoned Bergen miniature golf course, inhabited by a hidden colony of Pop Trolls who do not know that the Bergens are no longer their enemies, having been separated from the other Pop Trolls when they fled the final Trollstice. [a] The hidden troll colony's leader, Viva, reveals herself to be Poppy's long-lost sister. At first, Poppy is delighted, but the visit turns sour when Viva refuses to believe the Bergens have changed, and tries to stop Poppy's group from leaving the golf course. They manage to escape thanks to Clay, and Poppy and Viva separate with broken hearts.Meanwhile, Velvet and Veneer continue to strip Floyd of his essence. Velvet reveals that she forged Floyd's handwriting and sent a note to John Dory, in order to bait Floyd's brothers to come and rescue him. Furthermore, Velvet and Veneer's assistant Crimp invents shoulder-pad suits that enhance the extraction, which the siblings plan to use when they capture all of BroZone.The Trolls make it to Mount Rageous, but once again argue and fail to reach Perfect Family Harmony. When his brothers decide they will split up again after saving Floyd, Branch scolds them for abandoning their family and still treating him like a baby, reminding them that he lived his whole life alone after their grandmother got eaten. Branch, Poppy and Tiny locate Floyd on their own, but Velvet and Veneer capture John Dory, Clay, and Bruce, making a rescue even more difficult. Branch and Poppy confront Velvet and Veneer when they start mingling with a crowd of fans, prompting them to drive away in their limo. During the ensuing chase, Velvet and Veneer begin using the shoulder-pads to extract the essence from Branch's brothers in order to put on a show. Branch and Poppy are soon helped by Viva, who joined forces with Bridget and Gristle after they stumbled onto the golf course during their honeymoon.Seeing that Floyd is just about out of essence, Branch tells his brothers that they all simply need to put aside their egos and work as a team. They, along with Poppy and Viva, perform the Perfect Family Harmony and break free of their prisons just as Floyd loses the last of his essence, but he is quickly revived. Veneer, who had been second-guessing Velvet's machinations, publicly confesses everything, and they are sent to prison.The Trolls return to Vacay Island and witness BroZone's comeback concert, joined by Kismet, another band Branch was once part of. Later, Poppy and Viva join BroZone, under Branch's proposal, as honorary members.