The Ex-Files is the 4th episode of the second season and the 22nd overall.
Wakey wakey, Upper East Siders. Welcome to the first day of senior year and the onset of a new social dynastey. The big question is: with Serena single and on top of the world, will Constance become the House of van der Woodsen?
Vanessa discovers a scandalous secret about Catherine and enlists Blair's scheming expertise to use the information to help Nate. Meanwhile, Lily finds herself drawn back to her ex, Rufus, once again and Dan and Serena face off in light of their break up.
The episode begins with Serena, Eric, and Lily having breakfast discussing Lily's vacation with Bart. Chuck comes into the room and reveals to Lily that Dan and Serena broke up once again. He encourages Serena to take over being queen of Constance, but she declines and says that's Blair's thing. Chuck leaves with Eric for school, and Lily asks how Serena's doing. She replies that she's okay for now but seeing him every day will be hard. Meanwhile, in Brooklyn, Dan and Rufus are also discussing the breakup. Rufus encourages him to take things slow and Dan brings up his date who slept over and snuck out. Jenny comes out and explains that she's anxious over going to school due to Blair's organization of girls into groups: projects and victims. Dan mentions that he's glad he's not a girl.
At Constance, Blair is with her minions and combing through every girl there. She reviews their files and comments how every year the project pile shrinks and the victim pile grows. Upon arriving at school, Serena sees Dan in the courtyard and is visibly shaken up by the encounter. When she finishes the pile, Chuck brings a last file over to Blair and informs her of a new transfer. She tells him that after the stunt he pulled in The Dark Night, her and Marcus are better than ever. She quickly gets ready to leave to meet Serena without reviewing the file, and Nelly puts it in the project pile. At the same time, Nate ambushes Vanessa in Brooklyn and asks what happened with her and Catherine. She refuses to talk, and says they were never really friends and leaves him hanging.
Back at Constance, Dan is hanging with Jenny in hopes of seeing Serena. In the hall, Penelope, Nelly, and Isabel pass Jenny without saying a word. Jenny mentions to Dan that it's better to be ignored than tortured, and he agrees. He leaves to head over to the St. Jude's when he runs right into a girl named Amanda. He realizes she's reading a book by Jeremiah Harris, the author he interned for over the summer. The two begin talking, and Blair and Serena witness the whole thing. Afterwards, Blair reviews her file and mentions that while it's sketchy, she's a lot like Dan. Serena tells her she's making too big a deal out of it and insists she's fine. Meanwhile, Catherine goes to see Vanessa at the gallery. She gives her a check for respecting their agreement and not saying anything to Nate, and leaves before Vanessa can give it back. Back at school, Dan and Serena interact for the first time. They have an awkward conversation, and Dan asks to fast forward through their weirdness and be friends again. Serena agrees and asks him to have lunch with her. However, Amanda arrives and Dan declines and says he already had plans with Amanda. Serena quickly walks away and runs into Chuck, who mentions Dan and Amanda look very sweet together. He then sends a tip to Gossip Girl and when Blair sees the blast on the two together, begins to scheme.
In Brooklyn, Lily goes to see Rufus. He asks how her trip with Bart was and what brings her to the gallery. She says she just wanted to say hi and catch up. Rufus apologizes and says he's on his way out to see a showing of Repo Man. Lily invites herself, and Rufus agrees to let her come. At school, Blair and her minions invite Amanda to lunch. They tell her dating Dan is a bad idea, and Serena tells her to stop. Blair convinces her it's a good idea and they head off. At the same time, Vanessa goes to Catherine's to return the check but is told by the butler that she's unavailable. Vanessa goes to bring it to her anyway, and instead finds Catherine and Marcus about to have sex. She take photos and leaves.
At Constance, Chuck informs Dan that Amanda won't be joining him for lunch since she's with Blair and Serena; who only want to be her friend so she won't be able to date Dan. He doesn't believe Serena would act so maliciously, but Chuck asks him to prove him wrong. After he leaves, Dan receives a call from Vanessa who says she's having an emergency and needs to meet. At lunch, Serena mentions to Blair how wrong it feels to be using Amanda. Blair informs Amanda that dating friends' exes is off limits, meaning Dan. Amanda hesitantly agrees, and Serena begins to feel bad. She again tells Blair to stop and goes to find Dan to apologize. Meanwhile, Dan is meeting with Vanessa who shows him the pictures. She asks him what to do with the evidence to help Nate and his situation, and Dan tells her that she needs to go ask Blair for help. She doesn't want to, but Dan insists that she'll know what to do. Later, Dan runs into Serena, who apologizes. Dan says she's trying to rationalize instead, and that he didn't expect Serena to enlist back up. Offended, Serena replies that she wouldn't need Blair to win if she really wanted to and leaves. Amanda approaches Dan, and asks him out for that evening. At the Waldorf penthouse, Vanessa goes to see Blair. She shows her the pictures, and a tearful Blair tells her not to say anything to anyone and promises to handle it. Vanessa reminds her that she only wants to help Nate and that she's trusting her; and Blair replies that she has no choice. That same evening, Dan and Amanda go to a popular restaurant for dinner. Penelope and Isabel are also there, and tip off Gossip Girl that they're on a date.
The next day, Jenny tells Dan that Serena didn't deserve to find out that way and that he needs to apologize. Also, Chuck informs Serena about Dan's date the night before via the GG blast. When she arrives at school, Jenny finds Vanessa there, who is looking for an absent Blair. She asks her to help find her, and Jenny risks being put back on the mean girls' radar when she asks. She finds out she's having brunch, and Penelope tells her that they haven't forgotten her they're just picking their moment. Elsewhere in the building, Dan tries to apologize to Serena. She tells him that herself, Dan, and Amanda are going to hang out that night to get over the awkwardness. Dan is weirded out by the idea, but agrees. Vanessa tracks Blair down where she's having brunch, and sees her having a seemingly romantic meal with Marcus and leaves. However, Blair is about to confront both Marcus and Catherine. Marcus says it's only happened a few times and it hasn't happened since he met Blair. At that moment, Catherine arrives and demands to know what's going on. Blair sends her the pictures, and tells her they needs to discuss their exit strategy. Meanwhile, Vanessa goes to see Catherine's husband to tell him about her and Marcus.
On their "date", Dan and Amanda discuss literature and Serena becomes increasingly bored. She runs into Penelope and Isabel who introduce her to the captain of Dalton's lacrosse team, and she decides to mess with Dan and bring the guy over. At the table, he bores everyone with his lacrosse tales but Serena rubs it in Dan's face anyway. When she goes to get another drink, Dan confronts her about it. Serena says she didn't plan it but that she thought it was okay that they date other people. After a short argument, they decide to stay away from each other for a while. At the same time, Blair has Nate over to her penthouse to explain the Catherine and Marcus situation. She tells him about their affair and that she was able to get Catherine to agree to pay his father's restitution in exchange for her silence. However, in the midst of telling him, Catherine calls informing her that Vanessa told the Duke about them and the deal is off. Back at the restaurant, Chuck asks Penelope to make a Nairtini to get Amanda and she agrees. Also, Lily goes to see Rufus at the loft and asks him to be her friend. He rejects her, telling her she made her choice to marry Bart and she needs to do that. His date shows up and he introduces her to Lily. On her way out, she gives Rufus a bottle of champagne that used to be his favorite.
Blair goes to confront Vanessa. Vanessa tells her that the Duke promised the Captain would be safe, but Blair informs her that she messed the deal up and now Nate isn't going to have his old life back thanks to her. She leaves and Vanessa is visibly shaken knowing she ruined things. At the restaurant, Penelope finishes making the concoction and spills it on Amanda's hair, which immediately begins falling out in clumps. Embarrassed, she flees the restaurant. Serena apologizes to Dan, but he isn't interested in hearing it. He leaves, and Serena tells Penelope and Isabel that they are to do nothing else, and rises to the top once again.
The next morning, Vanessa goes to apologize to Nate. He's more hurt by the fact that she lied to him and confided in Dan and Blair and not him. He blows her off and heads to school. At Constance, Penelope and Isabel begin to bully Jenny. She decides to skip school and go to Waldorf Designs to work instead. Dan tries to call Amanda, but she isn't picking up or calling him back. However, it's revealed that she was hired by Chuck to make Serena jealous in order to dethrone Blair. When Blair arrives at school, the minions blow her off when Serena shows up and she realizes in her absence, Serena became the new queen. She runs into Chuck, who comments on Serena's rise to the top. Blair doesn't reply and walks off. Meanwhile, Dan arrives at school and is ignored and shunned by everyone who's path he crosses. The final shot is of Serena shaking her head at him as she leads her new army away.
- Blake Lively as Serena van der Woodsen
- Leighton Meester as Blair Waldorf
- Penn Badgley as Dan Humphrey
- Chace Crawford as Nate Archibald
- Taylor Momsen as Jenny Humphrey
- Ed Westwick as Chuck Bass
- Jessica Szohr as Vanessa Abrams
- Kelly Rutherford as Lily van der Woodsen
- Matthew Settle as Rufus Humphrey
- Connor Paolo as Eric van der Woodsen
- Amanda Setton as Penelope Shafai
- Mädchen Amick as Catherine Beaton
- Patrick Heusinger as Marcus Beaton
- Yin Chang as Nelly Yuki
- Nicole Fiscella as Isabel Coates
- Laura Leigh as Amanda Lasher
- Michelle Hurd as Laurel
- Purva Bedi as Clare
- Morning Tide by The Little Ones
- Electric Feel by MGMT
- Buildings and Mountains by The Republic Tigers
- Good Day by Nappy Roots
- Please Remain Calm by Cloud Cult
- The Observer by Chris Chavez
- Hold Up by Young Mennace
- Shove It by Santigold (ft. Spank Rock)
- Down' My Thang by King JuJu
Chuck (to Lily): Welcome home.
Serena: Say mom and I will kill you in your sleep.
Chuck: Decaf, Serena, I was going to say Mrs. Bass.
Nate: So, what, we're not even friends now?
Vanessa: We were never really friends, Nate.
Jenny (seeing the minions walk by without acknowledging her): It-it was like I didn't even exist.
Dan: Welcome to my world. It's not so bad once you get used to birds flying into your head and automatic doors never opening.
Blair: S, this girl is Dan with boobs. Do you really want to see them read together all year?
Dan (to Vanessa): Google revenge and get blairwaldorf.com.
Serena (to Dan): Just so you know, if this were a competition, I wouldn't need Blair and her posse to win.
Blair (to Marcus): I thought my family was twisted but you people take the cake.
Serena: Classy? Like you asking another girl out our first day back at school?
Dan: We were broken up!
Serena: So what Dan, it hurt! I loved you, and just because we broke up doesn't mean I can just turn it off like that.
Dan: You should wear a bell.
Chuck: Kinky, I'll think about it.
Blair (to Vanessa): I told you to do nothing! What, was that too difficult?
Dan (to Serena): You used to tell me that you were afraid people couldn't see the real you. Well, maybe you're the one who can't see yourself. From where I'm standing, this is who you are.
- The episode title is based off the movie The X-Files.
- The character Amanda Lasher is named for a producer of Gossip Girl with the same name.
- Harry Dean Stanton - Rufus mentions he loves this actor from the movies "Repo Man", "Paris, Texas" & "Pretty In Pink".
- Hannah Montana - Jenny compares Amanda to this fictional pop-star Disney character.
- Letters to a young poet - Amanda mentions this book of a collection of 10 poems by Rainer Maria Rilke.
- Mitchell Albom - Dan mentions this American author.
- Paris,Texas - Serena mentions this classic 1964 movie.
- Pretty In Pink - Lily brings this 1986 movie over to watch with Rufus.
- The Knicks - Blair mentions this New York basketball team.
- Tuesdays with Morrie - Dan mentions that Serena never read this book written by Mitchell Albom.
- Rainer Maria Rilke- Amanda mentions this 20th century famous poet.
- Repo Man - Rufus mentions he's going to watch this sci-fi movie at the sunshine theatre.
- Tory Burch - Blair mentions a pair of flats made by this fashion designer.
- Adirondack Mountains - A mountain range in upstate New York.
- Beijing - Lily mentions that Bart is in the city, which is the capital of China, for business.
- Centolire - Blair had brunch at this Italian restaurant located on Madison Ave.
- STK Restaurant - The restaurant/bar that Dan & Amanda were at on their date.
Food & Drink
- Belvedere Martini - Serena orders this martini made with vodka.
- Champagne - Chuck mentions he has champagne in the limo to drink on the way to school.
- Gelato - Serena asks Amanda to go to a cart and buy some gelato as a treat.
- Lump Crab - Isabel says,"I'm not going to share my lump crab", which is the extra large portions of meat that come out of a crab body.
- Valpolicella Wine - Lily hands a bottle of this wine to Rufus and says it used to be his favourite wine.