How about an extra helping of drama this holiday season? It just wouldn't be Thanksgiving on the Upper East Side without it. Blair suspects her mom (recurring guest star Margaret Colin) has been keeping a big secret from her, but it turns out to be something else entirely. Vanessa is supposed to spend Thanksgiving with her parents, but has a fight with her mom (recurring guest star Gina Torres) and shows up on Dan's doorstep. Meanwhile, Rufus learns that Lily has been lying to him about her mother, Cece (recurring guest star Caroline Lagerfelt), and Chuck tells Nate that he has some potentially damaging information about one of their friends. Plus, Jenny learns that Eric (recurring guest star Connor Paolo) was behind her very public embarrassment at Cotillion and can't pass up a chance to get even. And Serena is put in a very awkward position when her mother invites Tripp (recurring guest star Aaron Tveit) and Maureen (recurring guest star Holley Fain) to join them for Thanksgiving dinner.