Two decades after their escape from the clutches of the villainous Bergens, the bright-haired and perpetually cheerful Trolls are found by their old enemies. When the Bergen Chef (Baranski) captures a number of Trolls and takes them back to Bergen Town to be eaten, Troll princess Poppy (Kendrick) sets out on her own to rescue them, despite being urged by the grey and gloomy Troll Branch (Timberlake) to keep herself safe. Soon, Branch joins her on her dangerous quest, and together the pair of Trolls begin a mission not only to rescue their friends, but to teach the Bergens how to feel happiness.
It's only been a year since his wife's death, and widower Walter (Glover) wants only one thing for Christmas: for his whole family to come together and enjoy the holidays like they used to. His kids are all grown up now, and come with their own baggage and problems. Cheryl (Elise) is successful, happily married and doesn't get on with her younger sister, the recently divorced and financially struggling Rachel (Union). Christian (Malco) is running for Congress and can't seem to put his cellphone down, while youngest child, Evan (Usher), is an athlete struggling with an addiction to pain medication. As Christmas Day draws ever closer, it's Aunt May's (Mo'Nique) sense of humor that helps them set aside their problems and come together as a family.
Swede (McGregor) and Dawn (Connelly) Levov become increasingly worried about the radicalization of their teenage daughter, Merry (Fanning), during the Vietnam War. When a large bomb is set off, killing a man, Merry is named as the prime suspect and disappears, sending Dawn into a spiral of anguish and Swede on a desperate search to find his missing daughter.