Blair is feeling heartbroken and guilty by the current state of her relationship with Nate and her recent indiscretion. But she manages to put on a happy face for her 17th birthday party and attempts to hide her feelings from her friends. Hoping that Serena and Vanessa can bond, Dan takes Vanessa to Blair's birthday party. Jenny brings her mother home as a surprise, but Rufus isn't ready to forgive and forget. Finally, Nate's parents ask him to make a huge sacrifice to save his father's business.

Dan invites Serena and her family to spend the holiday with his family, creating an uncomfortable situation for Rufus and Lily. The children are unaware of their complicated romantic past. Meanwhile, Blair's freaks out when she learns that her father isn't coming home for Thanksgiving. Nate spends the holiday with his family, but their awkward dinner quickly goes from bad to worse.

Serena's grandmother announces that Serena has to go to Debutante Ball. However, Dan is not what CeCe wants as an escort for Serena, and she makes her opinion heard loud and clear, causing a rift between Serena and Dan. Although they are officially broken up, Nate asks Blair to go to the ball with him. A jealous Nate begins to suspect that Blair is seeing someone else. Jenny finds herself having to make the decision of either attending her mother's art opening or following her dreams to the Debutante Ball, even though her parents don't want her to go.

Blair's father, Harold, comes home for the holidays with an unexpected guest. Blair cannot hide her disappointment and makes a plan to get rid of Roman forever. Jenny and Vanessa help Serena get the best Christmas present ever for Dan, who has a surprise of his own for Serena. Rufus refuses to remain the understanding husband any longer after Alison's former lover sends a letter to the house.