Larry Nooly and his family are going to the Lodge at beautiful Lake Mulloon, the most perfectly happy place you can possibly imagine. That is, of course, until the Grinch checks in and everyone else checks out...except Larry.

Mrs. Zabarelli has been in charge of the town's Jingle Day Pageant for 49 years, but this year, she's put the show in the hands of her young student, Annie DeLoo. One by one the frustrated cast leaves until only Annie, Horton the Elephant and his son Morton are left to put on the pageant and make the sun rise on Jingle Day.

Max, the Grinch's dog, has saved a baby's life and won the hearts of everyone. Mayor Stovepipe invites the new hero to live in the mayoral mansion, leaving the Grinch alone, interviewing new candidates for a pet and not missing Max at all...maybe.

Thidwick is so excited...it's his birthday, and just like every other year, the Birthday Bird will take him (and all of the other birthday celebrants) to Katroo for a huge party. But when word comes that the Birthday Bird is unable to make it this year, Thidwick decides to take charge and lead everyone to Katroo himself...disguised as the Birthday Bird!