It's Christmas time once again and Scott Calvin juggles a full house of family and the mischievous Jack Frost, who is trying to take over the big guy's holiday. At the risk of giving away the secret location of the North Pole, Scott invites his in-laws to share in the holiday festivities, and upcoming birth of baby Claus with expectant wife, Carol. Along for the adventure are Scott's extended family, son Charlie, ex-wife Laura Miller, her husband, Neil Miller and their daughter, Lucy who, together with head elf Curtis, foil Jack Frost's crafty scheme to control the North Pole.