Meg and Michael’s annual holiday celebration is well underway, with a throng of out-of-town relatives staying at their house. Hosting these festivities is a little harder than usual―they have to relocate all the events normally held in their library, currently occupied by Roderick Castlemayne, the irascible wildlife artist who’s creating twelve paintings of birds to illustrate Meg’s grandfather’s latest nature book.

Still, the celebrations continue―and the entire family rejoices to learn that Meg’s brother Rob and his longtime fiancée Delaney have finally decided to tie the knot. Unfortunately, they decide to do this in the middle of Meg and Michael’s annual New Year’s bash, dashing their mothers’ hopes of planning the wedding to end all weddings.

Delaney’s mother sneaks into town so she and Meg’s mother can secretly plot a way to talk the happy couple into having a big bash. Hiding her only adds to Meg’s holiday stress―it’s almost a full-time job fending all the visitors who want to confront Castlemayne―reporters, bill collectors, process servers, and several ex-wives in search of unpaid alimony.