Gossip Girl(2007)

The privileged prep school teens on Manhattan's Upper East Side first learn that Serena van der Woodsen (Blake Lively, "The Sisterhood of the Traveling Pants") is back in town the way they learn all the important news in their lives -- from the blog of the all-knowing albeit ultra- secretive Gossip Girl. No one knows Gossip Girl's identity, but everyone in this exclusive and complicated vicious circle relies on her website and text messages for the latest scoop. Even Serena's closest friend, Blair Waldorf (Leighton Meester, "Entourage"), is surprised to find that Serena has suddenly ended her self-imposed exile to boarding school and returned to Manhattan. Once the Upper East Side's most notorious party girl, Serena's reasons for returning are mysterious, although they may have something to do with her younger brother Eric (Connor Paolo, "Alexander"). Whatever the reasons, the change in Serena is obvious, especially to Blair, whose friendship with Serena has always been competitive and difficult.

In the wake of the scandalous Kiss on the Lips party, Serena receives an ice-cold reception from her best friend, Blair, who reveals that she knows Serena slept with her boyfriend, Nate, before mysteriously running off to boarding school. Serena decides to take Dan to archenemy Chuck's fundraiser brunch at The Palace. And Jenny seeks advice from Blair, who realizes she may have something to gain by allowing Jenny into her inner circle.

As the Upper East Side teens from Constance Billard and St. Jude's prepare for a much-anticipated visit from Ivy League representatives, Blair uncovers scandalous information about Serena that may not remain a secret much longer. Dan has his heart -- and future -- set on serving in the coveted usher position for the Dartmouth representative. But he is beat out by Nate, who has no interest in the school, despite pressure from his controlling father, the Captain (recurring guest star SAM ROBARDS). Meanwhile, Jenny bonds with Serena's younger brother, Eric (recurring guest star CONNOR PAOLO). And Rufus must swallow his pride and ask Lily for a favor to help his son, Dan.

Blair is thrilled when her mother chooses her to be the new face of her clothing line. However, Blair's happiness soon turns to feelings of betrayal and jealousy when Serena moves into the spotlight, and Blair finds herself back in Serena's shadow. Meanwhile, Serena and Dan are reminded once again that they come from two very different worlds. And Nate and Chuck indulge in a boys' weekend to blow off steam after Ivy Week.

Dan makes elaborate plans to impress Serena on their first official date. On the same night, Jenny is invited to the infamous Blair Waldorf sleepover and finds herself in a high-stakes game of Truth or Dare. Meanwhile, when Lily discovers that Eric (recurring guest star CONNOR PAOLO) is missing from his treatment center, she seeks help from her ex- boyfriend, Rufus.

Dan is torn between two girls when his childhood friend, Vanessa (recurring guest star JESSICA SZOHR), returns home and declares her feelings for him, just as he and Serena are trying to figure out what they mean to each other. At her infamous masked ball, Blair sends Nate on a scavenger hunt, but he is still distracted by his feelings for Serena. Although Blair makes it perfectly clear that outsiders are not welcome, a disguised Jenny and Dan sneak into the ball. Meanwhile, Lily asks Rufus to accompany her to an event hosted by Blair's mother in order to make Chuck's father, who brought a model ("America's Next Top Model" winner CARIDEE ENGLISH) as his date, jealous.

After surviving their relationship's on-again/off-again genesis, Serena and Dan finally acknowledge that they are crazy about each other, despite their polar-opposite worlds that constantly threaten to pull them apart. Chuck contemplates investing in a burlesque club, hoping to make his hard-to-please father, Bart (recurring guest star ROBERT JOHN BURKE), proud of him. Nate confronts his father, the Captain (recurring guest star SAM ROBARDS), about the drugs he found in the house, but the Captain denies having a problem. Jenny discovers a secret that her father, Rufus, and mother, Alison (SUSAN MISNER), have been keeping from her. And Blair is once again devastated by Nate's actions after Jenny reveals that Nate accidentally kissed her, thinking she was Serena.

Devastated by the state of her relationship with Nate and still dealing with the guilt from a recent indiscretion, Blair puts on a happy face for her 17th birthday party and attempts to hide the truth from her friends. Hoping to ease the tension between Serena and Vanessa (recurring guest star JESSICA SZOHR), Dan takes Vanessa to Blair's party so the girls can have some bonding time, but this only ends up making Serena more uncomfortable. Meanwhile, Jenny brings her mom (recurring guest star SUSAN MISNER) home for a surprise visit, but Rufus may not be ready to forgive and forget. And Nate's parents ask him to make a huge sacrifice in order to salvage the business of his father, who faces charges of embezzlement and fraud.

When Dan finds out that Serena and her family are celebrating Thanksgiving alone, he naïvely invites them to spend the holiday with his family, creating an uncomfortable situation for Rufus and Lily, whose children are unaware of their complicated romantic history. Meanwhile, Blair's emotions spiral out of control when she learns that her father isn't coming home for Thanksgiving. Nate marks the holiday with his mom and dad, but their awkward dinner quickly goes from bad to worse.

Serena has absolutely no intention of attending the upcoming Debutante Ball, until her grandmother, CeCe (guest star CAROLINE LAGERFELT - "All the King's Men," "Nash Bridges"), announces that Serena must attend. Unfortunately, CeCe does not find Dan to be the "suitable escort" she had in mind for Serena, and makes her opinion heard loud and clear, causing a riff between Serena and Dan. Blair and Nate, now officially broken up, decide to go to the ball together as friends; however, Nate becomes jealous when he begins to suspect that Blair may already be seeing someone else. Meanwhile, Jenny finds herself torn between attending her mother's (recurring guest star SUSAN MISNER) art opening or following her dreams of going to the Debutante Ball, even though the latter is against her parents' wishes. And Rufus finally learns the real reason Lily broke up with him all those years ago.

When Blair's father, Harold (recurring guest star JOHN SHEA), comes home for the holidays with an unexpected guest -- his boyfriend, Roman (guest star WILLIAM ABADIE - "Entourage," "The O.C.," "The Pink Panther") -- Blair finds it difficult to hide her disappointment and hatches a plan to get rid of Roman for good. Meanwhile, Jenny and Vanessa (recurring guest star JESSICA SZOHR) help Serena plan the best Christmas surprise ever for Dan; Dan, in turn, may be thinking of his own surprise for Serena. And when Chuck texts Blair from Monaco saying that Nate has joined him there, Blair worries that Chuck may disclose the details of their hook-up. Back in Brooklyn, Rufus refuses to remain the understanding husband after a former lover of Alison's (recurring guest star SUSAN MISNER) calls the house.

The gang breaks into the school swimming pool for an impromptu night of fun, but when a member of their group nearly drowns, the school threatens to expel the person responsible for the break-in. Everyone agrees to keep a secret pact and say nothing, but it ultimately creates major tension between Serena and Dan, who isn't sure he's ready to risk his future and take the fall for someone else. Meanwhile, Vanessa (recurring guest star JESSICA SZOHR), who is working on a documentary project about private schools, accidentally captures Blair and Chuck discussing their affair, and Lily contemplates telling Rufus how she really feels about him.

Gossip Girl takes pleasure in reporting that Serena van der Woodsen has been spotted buying a pregnancy test, and the word spreads like wildfire. Of course, on the Upper East Side, the truth is often juicier and more scandalous than the gossip, and this time is no exception.

Having recently been dethroned as Queen Bee in the last episode by Gossip Girl, with an assist from scheming "little J," Blair hesitantly returns to school with the support of her BFF, Serena. Meanwhile, Serena struggles to adjust to her new living arrangements with her future stepbrother, Chuck, while receiving disturbing packages from an unknown sender. And Jenny's drive to be popular hits a new all-time high when she does something illegal to fit in with her new Upper East Side friends.

Serena's Upper East Side world is turned upside down when her former partner in all things bad, Georgina Sparks (recurring guest star MICHELLE TRACHTENBERG - "Buffy the Vampire Slayer," "Six Feet Under"), returns to Manhattan to stir up trouble -- and Serena's past. When Dan notices that Serena seems preoccupied, he jumps to the conclusion that it must have something to do with Serena's new roommate and soon-to-be stepbrother, Chuck. Meanwhile, Nate finds romance with the last person he was expecting to connect with, Vanessa, and Jenny meets a new guy, Asher Hornsby (recurring guest star JESSE SWENSON), who just might be her ticket to permanent popularity. Plus, Blair hatches a secret plan to sabotage her biggest rival, Nelly Yuki (guest star YIN CHANG - "Law & Order: Criminal Intent," "Six Degrees").

Georgina (recurring guest star MICHELLE TRACHTENBERG) informs Serena that she is prepared to reveal damaging information from Serena's past, but no one is ready for what Georgina does next. Blair and Jenny escalate their "popularity war" by spreading scandalous rumors about each other through Gossip Girl. Dan witnesses Jenny's new boyfriend, Asher (recurring guest star JESSE SWENSON), cheating on her, but Jenny refuses to listen to her brother's warning. Rufus goes to Lily for advice on how to handle Jenny's recent out-of-character behavior. Plus, one of the Upper East Side teens reveals that he is gay.

Georgina (recurring guest star MICHELLE TRACHTENBERG) reveals the true reason that Serena fled Manhattan for boarding school, and Serena quickly falls back into her old habits. Blair, Nate and Chuck must put their complicated feelings for each other aside to help their friend. Unfortunately, Serena is too ashamed to share the truth with Dan, leaving him to assume the worst about his girlfriend. Meanwhile, Rufus is thrilled when his band is invited to perform at a Rolling Stone-sponsored concert, but Lily is the last person he expects to see at the performance, especially since her wedding rehearsal dinner is the same night. Recording artist LISA LOEB and famous cake designer SYLVIA WEINSTOCK appear as themselves.

With Serena's life and reputation on the line, Blair -- as Serena's best friend -- decides to take matters into her own hands to deal with the manipulative and evil Georgina Sparks (recurring guest star MICHELLE TRACHTENBERG). Lily prepares for her wedding day, which is destined to be the Upper East Side's social event of the year, and finds that Rufus is never far from her thoughts. Serena finally opens up to Dan, pours out her heart and tells him the truth about her past, but will it prove to be too late to save their relationship? And Lily's interior decorator, Amelia (heiress and model LYDIA HEARST), makes a big impression on Chuck.

Gossip Girl heads to the Hamptons as summer comes to a close. Guest stars include author JAY McINERNEY (Bright Lights, Big City), socialite TINSLEY MORTIMER and MADCHEN AMICK.

Blair is over the moon to be dating royalty and has every intention of becoming a royal herself, but a scheming Chuck has other plans for Blair and her new love, Marcus (recurring guest star PATRICK HEUSINGER). Serena and Dan agree to keep their recent hookups a secret from their friends and family until they figure out what it means for their relationship. Meanwhile, Nate learns the downside to having an affair with a hot older woman, Catherine (recurring guest star MADCHEN AMICK), who is married.

Serena and Dan are forced to deal with their unspoken problems while trapped in an elevator during a citywide blackout. In a humorous twist, Blair questions the lack of passion in her relationship with Marcus (recurring guest star PATRICK HEUSINGER), while, at the same time, Chuck appears to have lost his "passion" for any woman other than Blair. Meanwhile, Nate struggles between his feelings for Vanessa and his more-complicated-by-the-day relationship with Catherine (recurring guest star MADCHEN AMICK). Plus, Jenny risks losing her internship when Eleanor (recurring guest star MARGARET COLIN) catches Jenny critiquing one of the Eleanor Waldorf designs.

When Serena notices that Dan has been cozying up to the new girl in school, Amanda (guest star LAURA-LEIGH), the ever-loyal Blair and her minions decide to befriend Amanda and sabotage her budding new romance with "lonely boy." Plus, Vanessa discovers a scandalous secret about Catherine (recurring guest star MADCHEN AMICK) 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.

Blair decides to sabotage her mother's show at Fashion Week. Dan starts hanging out with Chuck, and learns the hard way that a walk on the dark side always has its risks. Designer MICHAEL KORS and socialites TINSLEY MORTIMER and CRISTINA CUOMO make cameo appearances at Eleanor Waldorf's show.

After a fight, Serena wants to get even with Blair -- who dreams of attending Yale University -- and accepts an invitation to visit. Chuck is kidnapped by an elite secret society.

Blair seeks revenge by enticing Chuck to seduce Vanessa. Serena rebels at an important party of Lily's. And Dan and Jenny find out a secret Nate has been hiding from his friends.

Jenny befriends a model (WILLA HOLLAND - "The O.C."), and is encouraged to explore her wild side. Serena is attracted to an artist, Aaron Rose (JOHN PATRICK AMEDORI - "Vanished").

Serena realizes Aaron (JOHN PATRICK AMEDORI) has kept a secret from her. Jenny and Agnes (WILLA HOLLAND) plan a guerilla fashion show. Blair babysits the daughter of a Yale donor.

Dan tries to get close to Bart Bass (recurring guest star ROBERT JOHN BURKE) to possibly write an exposé, but things get heated when Chuck finds out. WALLACE SHAWN guest stars.

Blair's favorite Thanksgiving traditions are ruined by her mother's new boyfriend (WALLACE SHAWN). Serena doesn't tell Aaron (JOHN PATRICK AMEDORI) about her past -- but Dan does.

At the annual Snowflake Ball, Blair and Chuck bet they can find ideal dates for each other. Aaron's (JOHN PATRICK AMEDORI) ex-girlfriend (NATALIE KNEPP) shows interest in Dan.

A sudden and tragic event impacts the lives of everyone.

Chuck's uncle, Jack Bass (recurring guest star DESMOND HARRINGTON - "Dexter," "Rescue Me") arrives on the scene. Meanwhile, Jenny returns to school and takes on the mean girls.

Bart's will is read and everyone learns the fate of the Bass empire. Plus, Dan discovers the secret between Rufus and Lily, and must decide what to do with the information.

Which students will be accepted to Yale University? Plus, Chuck pairs up with an unlikely ally in his war with Jack (recurring guest star DESMOND HARRINGTON) over Bass Industries.

Blair comes up with a plan to get revenge on her teacher, Rachel (LAURA BRECKENRIDGE). Chuck wakes up in a hotel and tries to piece together what happened the night before.

The seniors put on a production of "The Age of Innocence." Chuck enlists help from an unlikely source -- his nemesis, Carter Baizen (SEBASTIAN STAN - "Kings," "The Covenant").

Devastated by the recent plot twist in her life, Blair turns her back on her predictable existence in favor of a wilder lifestyle, causing Serena and Chuck to be concerned.

Serena throws Jenny a party for her 16th birthday, but things get way out of control when Poppy Lifton (TAMARA FELDMAN) turns the small gathering into a huge social event.

Serena returns from her trip to Spain with Poppy (recurring guest star TAMARA FELDMAN) and Gabriel (recurring guest star ARMIE HAMMER). Blair makes a secret deal with Nate's grandfather, William (recurring guest star JAMES NAUGHTON - "The Devil Wears Prada"), and Nate learns some disturbing information about his father's arrest. Meanwhile, Dan takes a job as a cater-waiter to earn money for college, but is distressed when he discovers the gig is a Passover Seder at the Waldorf penthouse, where several of his friends and family will be guests.

Georgina (recurring guest star MICHELLE TRACHTENBERG) returns to the Upper East Side after undergoing a major transformation. Chuck and Nate find themselves at a major crossroads in their friendship, a result of their mutual interest in Blair. And Serena finds her relationship with Gabriel (recurring guest star ARMIE HAMMER) growing more complicated.

Blair pressures Georgina (recurring guest star MICHELLE TRACHTENBERG) to help her in a scheme to make amends for her past bad behavior. The rivalry between Nate and Chuck over Blair comes to a head. And Lily hatches a secret plan to help Rufus with Dan's college tuition.

In a special flashback to the 1980s, before she became Lily van der Woodsen, 17-year-old Lily Rhodes (guest star BRITTANY SNOW - "American Dreams," "Hairpray") is kicked out of boarding school and runs away to Los Angeles to reconnect with her parents, Rick (guest star ANDREW McCARTHY - "Lipstick Jungle," "Pretty in Pink") and CeCe (guest star CYNTHIA WATROS - "Lost"), and her older sister, Carol (guest star KRYSTEN RITTER - "Confessions of a Shopaholic"). Plus, NO DOUBT performs as an eighties band called Snowed Out. Back in present day New York City, Blair and Nate attend the prom together, but the evening doesn't turn out exactly as planned -- something Chuck may have a little to do with. And Serena and Lily don't see eye to eye over Serena's recent run-in with the law. Recurring guest star MICHELLE TRACHTENBERG appears as Georgina.

At the Constance Billard and St. Jude graduations, Gossip Girl livens things up by sending out a shocking and damaging email blast in the midst of the commencement ceremony, stirring Serena to come up with a plan of attack. The Mean Girls (recurring guest stars YIN CHANG, NICOLE FISCELLA, AMANDA SETTON and DREAMA WALKER) challenge Jenny to throw her hat in the ring to succeed Blair as Queen Bee next year, and Lily and Rufus struggle to repair their relationship after Lily's betrayal. Plus, the season finale is rife with cliffhangers: Blair and Chuck finally ... Serena is shocked by ... Georgina (recurring guest star MICHELLE TRACHTENBERG) decides to ... And Dan, Nate and Vanessa unknowingly .... OMG!

As the summer draws to a close, Blair (series star LEIGHTON MEESTER) and Chuck (series star ED WESTWICK) are madly in love and adjusting to their new "in a relationship" status, though breaking all traditional rules of dating, as would be expected. Serena (series star BLAKE LIVELY) returns from her European adventure with many secrets to hide and a complicated relationship with Carter Baizen (recurring guest star SEBASTIAN STAN - Kings). Nate (series star CHACE CRAWFORD) returns from his travels with a mysterious brunette, Bree Buckley (recurring guest star JoANNA GARCIA - Privileged, Reba) in tow. Rufus (series star MATTHEW SETTLE), Dan (series star PENN BADGLEY) and Jenny (series star TAYLOR MOMSEN) spent the summer in the Hamptons, adjusting to the van der Woodsen's glamorous lifestyle surprisingly faster than any of them expected. The series also stars JESSICA SZOHR as Vanessa and KELLY RUTHERFORD as Lily van der Woodsen Bass.

Blair, determined to maintain her Queen Bee status in college, embarks on her first day at NYU, along with Dan and Vanessa. Unfortunately, Georgina (recurring guest star MICHELLE TRACHTENBERG) turns up as Blair's roommate in the dorms, determined to make Blair a social outcast. As Serena prepares to depart for Brown, she and Chuck have a major falling out, so she recruits Chuck's enemy, Carter (recurring guest star SEBASTIAN STAN), to help her get even. Meanwhile, Nate and Bree (recurring guest star JoANNA GARCIA) decide to explore their relationship further, knowing full well it could cause tension between their families who are political rivals.

It's a bidding war on the Upper East Side. Blair and Chuck both set their sights on a particular item up for bid at Sotheby's, and the personal stakes are high. Plus, Serena suspects that Carter (recurring guest star SEBASTIAN STAN) may be up to his old habits, Georgina (recurring guest star MICHELLE TRACHTENBERG) takes an interest in Dan and Vanessa begins to suspect that something isn't quite right with Scott (recurring guest star CHRIS RIGGI - "Lipstick Jungle," "Dare").

It's the first day of school at Constance Billard which means it's also time for Jenny to take her rightful place as the new Queen Bee. Unfortunately for Jenny, Blair is more than happy to intervene when news reaches her that she may be needed back at Constance. Meanwhile, Lily returns home to Rufus and her family to find that things are definitely not as she left them. Plus, a famous movie actress, Olivia Burke (recurring guest star HILARY DUFF - A Cinderella Story, Material Girls, Lizzie McGuire), enrolls at NYU in hopes of having a somewhat normal college experience, and is assigned to be Vanessa's roommate. Guest star TYRA BANKS (The Tyra Show, America's Next Top Model) appears as Ursula, an actress co-starring in Olivia's movie and someone who Serena befriends.

Lily and Rufus decide to move up their wedding to the next day, but will someone or something come between them before they can become married? Chuck discovers a secret that Carter (recurring guest star SEBASTIAN STAN) has been keeping from Serena. Dan and Vanessa are pulled into one of Georgina's (recurring guest star MICHELLE TRACHTENBERG) schemes. Blair is suspect of Bree (recurring guest star JoANNA GARCIA) and shares her concerns with Nate. Musical group SONIC YOUTH performs.

Vanessa, hoping to finally win the approval of her mother, Gabriela (guest star GINA TORRES - 24, Alias, Firefly), desperately vies with Blair for the honor of delivering the freshman toast at NYU, but at what price? Dan invites Olivia (recurring guest star HILARY DUFF) to meet Rufus and Lily, which leads to all sorts of problems for the new couple. Serena and Nate team up to help Carter Baizen (recurring guest star SEBASTIAN STAN).

In need of publicity for his new hotel, Chuck decides to move up his club's opening and enlists Serena's help to get the word out to her celebrity clients. Feeling left out of the planning, Blair attempts to win Chuck's approval by secretly helping him with a problem concerning opening night. Dan is unnerved when he finally watches one of Olivia's (recurring guest star HILARY DUFF) infamous sex scenes with co-star and real-life boyfriend at the time, Patrick Robinson (recurring guest star SIMON MILLER - Elah and the Moon). Jenny is forced to choose between her relationship with Eric (recurring guest star CONNOR PAOLO) and her new role as Queen Bee. Plus, Rufus gets Lily into the Halloween spirit. Musician ALBERT HAMMOND JR. (The Strokes) performs.

Olivia (recurring guest star HILARY DUFF) says something she regrets during an appearance on a talk show with host JIMMY FALLON (guest starring as himself) and tries to keep Dan from finding out. With election day around the corner, Nate suspects his grandfather (recurring guest star JAMES NAUGHTON) will stop at nothing to get Tripp (recurring guest star AARON TVEIT) elected to Congress. In the midst of another feud with Serena, Blair befriends a new It girl. In an effort to make Serena jealous, Blair takes her new friend to an election night party at Chuck's hotel.

Not satisfied with just being Queen of Constance Billard, Jenny sets her sights on becoming the queen of all the Upper East Side by landing the hottest escort for Cotillion. Nate and Chuck plot to help Serena and Blair repair their damaged friendship. Dan is upset when Olivia (recurring guest star HILARY DUFF) contemplates leaving school for a movie project. Plus, all-girl French rock band PLASTISCINES performs.

Hoping to impress the elitist theater kids at NYU, Blair sets her sights on landing a private concert with the hottest musical performer of the year, LADY GAGA (in a special guest performance). Dan and Olivia (recurring guest star HILARY DUFF) sign up to write and star in a school play, based on an idea by Blair and directed by Vanessa. With Blair out of the picture, Serena turns to Nate to help her get through a difficult situation. As a favor to Chuck, Jenny agrees to hang out with Damian (recurring guest star KEVIN ZEGERS - Transamerica, The Jane Austen Book Club, Dawn of the Dead), the son of an ambassador who is staying at Chuck's hotel, but the experience proves to be a lot more intriguing than she expected.

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.

On the anniversary of the death of Bart Bass, Chuck wrestles with an issue from the past and a serious car accident rocks the Upper East Side. Dan and Vanessa attempt to navigate their newly complicated friendship. And when Jenny is accused of beating up one of her classmates, Eric (recurring guest star CONNOR PAOLO) is faced with a tough dilemma.

Nate and Serena explore the boundaries of their friendship. Blair suspects that Chuck is having problems forgetting about the woman (recurring guest star LAURA HARRING - The Shield, Mulholland Drive, Sunset Beach) he saw at his father's grave. Jenny agrees to help Damien (recurring guest star KEVIN ZEGERS) overcome a challenge he faces. Vanessa and Dan attempt to move past the awkwardness of Dan's confession of love. Rufus returns from a ski trip and tries his best to avoid Lily.

Chuck learns more about the woman (recurring guest star LAURA HARRING - The Shield, Mulholland Drive, Sunset Beach) who may or may not be his mother. Dan and Vanessa struggle through the awkwardness of dating other people. Plus, Rufus and Lily grow suspect of Jenny's relationship with Damien (recurring guest star KEVIN ZEGERS).

Jenny contemplates taking her relationship with Damian (recurring guest star KEVIN ZEGERS) to the next level, and Nate and Serena clash over how to handle the situation. Meanwhile, a bogus lawsuit threatens to shut down Chuck's hotel, and he suspects his uncle, Jack Bass (recurring guest star DESMOND HARRINGTON), is behind it. Chuck's doubt that his mother (recurring guest star LAURA HARRING) may not be who she claims to be could destroy their newly formed bond. Plus, Dan and Vanessa attempt to define the different "zones" of their relationship, and Lily and Rufus try to trust one another.

Chuck, once again, finds himself at odds with his uncle, Jack Bass (recurring guest star DESMOND HARRINGTON). Eleanor (recurring guest star MARGARET COLIN) puts Blair in charge of making sure her latest fashion show is a huge success with an important client. Rufus attempts to get Jenny back on track by volunteering to have her help with Eleanor's fashion show, but the opportunity takes a turn for the worse when Jenny learns that Agnes (recurring guest star WILLA HOLLAND) will be one of the models.

Chuck and Blair are faced with the most difficult decision they have ever faced as a couple. Serena plans a surprise birthday party for Nate, but Jenny does her best to sabotage Serenas's efforts. Meanwhile, Dan and Vanessa's new relationship hits a bump in the road.

Chuck offers to throw a wedding for a very pregnant Dorota (recurring guest star ZUZANNA SZADKOWSKI) who insists that she and Vanya (recurring guest star AARON SCHWARTZ) have a traditional wedding before her parents arrive from Poland and find their daughter pregnant and without a husband. Dorota asks Blair and Chuck to be part of the ceremony and walk her down the aisle. Serena tells Nate she is having breakfast with the Humphreys when in reality she is secretly meeting up with Carter Baizen (recurring guest star SEBASTIAN STAN). Plus, Rufus discovers that Lily has been lying to him about her whereabouts.

When Lily's ex-husband Dr. William van der Woodsen (recurring guest star WILLIAM "BILLY" BALDWIN -- Dirty Sexy Money, Backdraft), shows up unexpectedly in Manhattan, Serena finally gets the reunion with her father she has so desperately wanted — but the circumstances turn out to be far from ideal. Meanwhile, Serena and Nate continue to have relationship issues, and a scheming Jenny is more than happy to be a shoulder for Nate to lean on. Plus, Dan finds out that he didn't get accepted into the Tisch writing program and Vanessa admits she may have been somewhat responsible.

Will's (recurring guest star WILLIAM "BILLY" BALDWIN) return to the Upper East Side continues to stir up problems for Serena, Lily and Will's long-standing rival, Rufus. The relationship between Serena and Jenny is strained as a result of Jenny's deception. Blair spends time on the Columbia campus and realizes where she truly belongs. And Dan learns that Vanessa has been keeping yet another secret from him.

When things get tense between Rufus and Will (recurring guest star WILLIAM "BILLY" BALDWIN), Serena chooses to stand behind her father, while Rufus is made to feel like an outsider within his own family. Meanwhile, Jenny deliberately shares information with Will that may ultimately destroy Lily and Rufus' marriage. And, after many failed attempts, Chuck makes one last grand gesture to reconcile with Blair, hoping she will finally accept the fact that they are destined to be together.

In the third season finale, Blair must decide whether to meet Chuck at the top of the Empire State Building or risk losing their future together. A Gossip Girl gossip bomb involving Dan explodes Serena and Nate's relationship. Dorota (recurring guest star ZUZANNA SZADKOWSKI) and Vanya (recurring guest star AARON SCHWARTZ) welcome their baby. Jenny hits rock bottom. Plus, Georgina (recurring guest star MICHELLE TRACHTENBERG) returns to the Upper East Side ... and she has an agenda.