It’s been two years since siblings Kate and Teddy Pierce saved Christmas, and a lot has changed. Kate, now a cynical teenager, is reluctantly spending Christmas in Cancun with her mom’s new boyfriend and his son Jack. Unwilling to accept this new version of her family, Kate decides to run away. But when a mysterious, magical troublemaker named Belsnickel threatens to destroy the North Pole and end Christmas for good, Kate and Jack are unexpectedly pulled into a new adventure with Santa Claus.