Topanga is staying with Cory's family for Christmas. They're happy to have her, but tensions are raised when traditions begin to clash. Her family usually has cider, while the Matthewses are an egg nog family; she's used to a real tree, but they likes their aluminum tree; and unbelievably, she wants to open presents on Christmas Eve. She's able to incorporate her traditions with theirs, but the mood is uncomfortable. Eric voices his concern with Topanga's interference, but Cory just wants her to be happy.
He begins to get a little irritated, however, when she wakes him up in the middle of the night just to talk. Unable to get back to sleep, he goes downstairs and finds his father, who's in a similar situation, making model airplanes. Cory tells Alan he thought he and Topanga got along because they were so much alike, but as it turns out, they're very different.
The next morning Topanga makes him Christmas tree pancakes, but instead of syrup, she uses confectioner's sugar, to Cory's chagrin. He grins and bears it until she tells him that they're going caroling. He declines, "I can't sing. I don't like to sing. I get embarrassed when I sing." When she persists, "It's just singing", Cory's had enough, and he leaves to think things over.
He goes to Shawn's apartment, where Shawn and Jack are trying to come up with brotherly things to do this holiday. They realize they both love ice skating, so they leave while Cory takes a nap on their couch.
In his dream, Mr. Feeny appears as the Ghost of Christmas Future. He shows Cory a scene in which Eric is balding, and Cory is fat because he only eats Christmas tree-shaped pancakes with confectioner's sugar.
Feeny then takes him to see Topanga, who lives in a nice house and drinks hot cider. He's surprised to see that she married Jack, and they have three kids. When Topanga has the children open presents on Christmas eve, Cory berates her for always needing to have things her way. Mr. Feeny points out the aluminum tree, and tells Cory that love is about compromise.
Back in the Matthewses kitchen, Topanga is sad because she chased Cory away. She's sitting in contemplative silence, when Cory appears in the doorway, singing a wavering version of "The First Noel". Topanga smilingly lets him in and he gives her a present. It's a tiny box with a bow on it. "It's a promise ring," he says. "It means that we're going to be together forever." She gives him a present too: a similar box with an identical bow. "It's a promise ring."