Jimmy Fallon and Hillary Duff guest star— Olivia (guest star Hilary Duff) says something she regrets during her appearance on Jimmy Fallon’s (Fallon playing himself) talkshow and tries to keep Dan (Penn Badgley) from finding out. With election day around the corner, Nate (Chace Crawford) suspects his grandfather (guest star James Naughton) will stop at nothing to get Trip (guest star Aaron Tveit) elected to congress. In the midst of another feud with Serena (Blake Lively), Blair (Leighton Meester) befriends a new “it” girl and takes her to an election night party at Chuck’s (Ed Westwick) hotel, hoping to make Serena jealous. Taylor Momsen, Jessica Szohr, Kelly Rutherford and Matthew Settle also star. Mark Piznarski directed the episode written by Lenn Rosenfeld.
PHOTOS: Gossip Girl "The Grandfather"