Frankie's parents, Pat (guest star Marsha Mason) and Tag (guest star Jerry Van Dyke), invite the Hecks to spend a few days at their house to celebrate Thanksgiving. They aren't the only ones coming home for the holidays. Frankie's sister, Janet (guest star Molly Shannon), and her family are also in the house. The other family gets there first to claim the guest room. That's fine. Mike knows where the air mattresses are since they used them last year, too.
Pat prepared most of this year's Thanksgiving meal back in July. So the stuffing and sweet potatoes have been sitting in the freezer for about four months. It gives Pat more time to engage in family gossip with her daughters. Sue is invited to the gabfest this holiday season since she recently matured as a woman. Sue is totally jazzed to finally be a member of the blah-blah sisterhood.
With no TV in the house, Mike is happy to make a mini-mart run where he witnesses Axl's lame attempt to flirt with the cute cashier. Mike tries to show his boy some slick pickup moves. He bombs in the most inappropriate of ways. After that, Tag goes in for the kill. Let's just say smoothness with the ladies is not something that runs in this particular family.
Brick is forced to play with his pampered cousin, Lucy. Janet babies her daughter beyond belief. Coddling is a parenting technique that Frankie never employs, so there's tension in the house when cousins collide. When Lucy's stuffed bear is trashed in the snow, Brick gets blamed for this Thanksgiving tragedy. He uses an old detective kit game to try to clear his name, though he'd have been better off leaving this as a cold case.
Frankie is stunned when Janet hints that she should buy Lucy a new bear at the mall. She vents her frustrations to her mom over a glass of wine. Later, Pat gets Janet's version of things over even more wine. Eventually, the two sisters have a full-scale blowout which culminates with a serious smackdown with the air mattress.
After the quietest Thanksgiving dinner in Heck history, Frankie and Janet make nice during a late-night leftover raid of the fridge. The holiday visit ends with hugs as everyone heads back to their own homes. Frankie declares this a "perfect Thanksgiving." Mike wonders, "What Thanksgiving were you at?"