Freshly single, Dan returns to his childhood home for Christmas to find it's in various stages of disarray, with one functioning bathroom. As the extended family gathers for a welcome meal, Dan meets Cora, with whom he instantly clicks. There's only one problem: she's already dating his cousin.

In an unexpected turn of events, all the Moodys find themselves living under the same roof again when Bridget, who lives in the Chicago area, returns to her childhood home with a suitcase in hand after a fight with her husband.

Christmas caroling is a Moody tradition that Sean Sr. does not take lightly. However, when an unexpected guest shows up to the Moody house, caroling takes a hilariously embarrassing turn. Then, Sean Jr. finally agrees to join Sean Sr'.s Moody Heating and AC business, but trouble ensues when a rival company infringes on their territory.

Bridget finds someone in whom to confide, while Dan struggles with the guilt of being interested in cousin Marco's girlfriend, Cora.

With Christmas quickly approaching, Sean Sr. receives the top honor as the lector of Midnight Mass. Meanwhile, when Sean Sr. invites some unexpected guests to Christmas Eve dinner, Ann starts to unravel.

When the Moodys think things couldn't possibly get worse, they are faced with a devastating challenge. All Ann wanted was a nice, white Christmas!