4×01 Belles De Jour

Season Four kicks off in the city of lights! OMP!

Blair (Leighton Meester) has spent a fabulous summer in Paris without realizing her former love, Chuck Bass (Ed Westwick), has been shot. As much as Blair tries to distract herself from the pain Chuck caused her, his mysterious appearance in Paris with a beautiful new woman (guest star Clémence Poésy) will force both of them to face what happened. Meanwhile, a newly single Serena (Blake Lively) has been enjoying a Parisian summer of love with boys, Blair and Balenciaga as she tries to avoid the inevitable decision about which of her two long-time beaus, Dan or Nate (Penn Badgley and Chace Crawford), she should return to. Back on the Upper East Side, Nate meets an intriguing girl, Juliet (guest star Katie Cassidy, “Melrose Place�), who helps him realize that his summer of sexual conquests with the help of Chuck’s little black book was his way of avoiding his unresolved feelings for Serena. Meanwhile, Dan’s (Penn Badgley) baby mama drama continues with Georgina (guest star Michelle Trachtenberg). Finally, the van der Woodsen apartment is buzzing with activity as the “Fashion’s Night Out� event is planned. Jessica Szohr, Kelly Rutherford and Matthew Settle also star. Mark Piznarski directed the episode written by executive producers Joshua Safran and Stephanie Savage.

4×02 Double Identity

Gossip Girl goes Paris!

Living out a real-life fairytale in Paris, Blair (Leighton Meester) is pursued by a handsome young man, Louis (guest star Hugo Becker), who she suspects is a member of Monaco’s royal family. A very concerned Lily (Kelly Rutherford) asks Serena (Blake Lively) to help her find Chuck (Ed Westwick), who hasn’t been heard from or seen in months. Meanwhile, Chuck Bass is as we’ve never seen him before, adjusting to a fresh start in Paris with a mysterious new woman, Eva (guest star Clémence Poésy), at his side. Juliet (guest star Katie Cassidy) offers to help Nate (Chace Crawford) win Serena (Blake Lively) back, suggesting that reigniting Dan (Penn Badgley) and Vanessa’s (Jessica Szohr) romance may just be the trick to remove Dan from the Dan-Serena-Nate love triangle. Matthew Settle also stars. Mark Piznarski directed the episode written by executive producers Joshua Safran and Stephanie Savage.

4×03 The Undergraduates

Back to the Upper East Side!

On her first day at Columbia, Blair (Leighton Meester) attempts to gain membership into an ultra-exclusive social club, Hamilton House …. but she’s in for a few big surprises. Serena (Blake Lively) begins to suspect that Juliet (guest star Katie Cassidy) is intentionally sabotaging Serena’s life and that it may have something to do with Nate (Chace Crawford). Rufus (Matthew Settle) is worried about Dan (Penn Badgley) and decides to take matters into his own hands. Ed Westwick, Jessica Szohr and Kelly Rutherford also star. Norman Buckley directed the episode written by Amanda Lasher.

4×04 Touch of Eva

Nate suspects Juliet is keeping a secret

Nate (Chace Crawford) suspects that Juliet (guest star Katie Cassidy) is keeping a big secret from him and decides to confront her. Blair (Leighton Meester) schemes to undermine Chuck’s (Ed Westwick) newfound happiness. Dan (Penn Badgley) finds himself torn between his feelings for Serena (Blake Lively) and Vanessa (Jessica Szohr). Kelly Rutherford and Matthew Settle also star. Andrew McCarthy directed the episode written by Leila Gerstein.

4×05 Goodbye Columbia

A Gossip Girl blast strikes out against Serena

An anonymous Gossip Girl blast starts a very damaging rumor about one of Columbia’s new students, Serena (Blake Lively). On her path to greatness, Blair (Leighton Meester) decides to take a class with a powerful businesswoman, Martha (guest star Marilyne Barrett), who is guest-lecturing at Columbia, but a mysterious fellow student thwarts her plans to secure the prized position as Martha’s assistant. Penn Badgley, Chace Crawford, Ed Westwick, Jessica Szohr, Kelly Rutherford and Matthew Settle also star. Jeremiah Chechik directed the episode written by Robby Hull.

4×06 Easy J

Tim Gunn guest stars – Jenny’s (Taylor Momsen) Back!

Although Blair (Leighton Meester) made it perfectly clear that Little J was no longer welcome in Manhattan after what happened with Chuck (Ed Westwick), Jenny (Taylor Momsen) is tempted by a once-in-a-lifetime opportunity to meet Tim Gunn (Project Runway), which could be a game changer for her future. Meanwhile, Serena (Blake Likely) discovers something about her new boyfriend, Colin (guest star Sam Page), that may put an end to their relationship just as it was getting good. Penn Badgley, Chace Crawford, Jessica Szohr, Kelly Rutherford and Matthew Settle also star. Lee Shallat Chemel directed the episode written by Jake Coburn.

4×07 War at The Roses

Blair’s birthday party – Musical performance by Robyn

Blair (Leighton Meester) is caught off-guard – and not in a good way – by a surprise guest at her birthday party. Having had enough of Chuck (Ed Westwick) and Blair’s games, Serena (Blake Lively) and Nate (Chace Crawford) decide to plan an intervention. Musical guest Robyn performs in the episode. Penn Badgley, Taylor Momsen, Jessica Szohr, Kelly Rutherford and Matthew Settle also star. Joe Lazarov directed the episode written by Jessica Queller.

4×08 Juliet Doesn’t Live Here Anymore

Can Chuck and Blair really be friends?

Chuck (Ed Westwick) and Blair (Leighton Meester) decide it’s in both their best interests to put the past behind them and end their vindictive games. Nate (Chace Crawford) confronts Juliet (guest star Katie Cassidy) after discovering a secret she has been keeping from everyone. Dan (Penn Badgley) and Nate realize they both still have feelings for Serena (Blake Lively). Taylor Momsen, Jessica Szohr, Kelly Rutherford and Matthew Settle also star. Patrick Norris directed the episode written by Jeanne Leitenberg.

4×09 The Witches of Bushwick

Chuck throws a “Saints and Sinners” masquerade party

Chuck (Ed Westwick) hosts a “Saints and Sinners” masquerade party at the Empire Hotel. At the party, Dan (Penn Badgley) and Nate (Chace Crawford) don’t know what to make of Serena’s (Blake Lively) strange behavior and mixed messages. Blair (Leighton Meester) sets her sights on becoming the new face of Anne Archibald’s (guest star Francie Swift) foundation for girls, but Anne is concerned that Blair’s friendship with Chuck Bass may be problematic. Katie Cassidy guest stars as Juliet. Taylor Momsen, Jessica Szohr, Kelly Rutherford and Matthew Settle also star. Ron Fortunato directed the episode written by Sara Goodman.

4×10 Gaslit

Tate Donovan directs the episode

Chuck (Ed Westwick), Serena (Blake Lively), Blair (Leighton Meester), Dan (Penn Badgley), Jenny (Taylor Momsen) and Eric (Connor Paolo) find themselves faced with a crisis when a member of one of their families is hospitalized. Meanwhile, Nate (Chace Crawford) attempts to help his parents, The Captain (guest star Sam Robards) and Anne (guest star Francie Swift), put their complicated past behind them and reconcile. Katie Cassidy guest stars as Juliet. Jessica Szohr, Kelly Rutherford and Matthew Settle also star. Tate Donovan directed the episode written by Joshua Safran and Robert Hull.

4×11 The Townie

Katie Cassidy and Kevin Zegers guest star

Blair (Leighton Meester) and Dan (Penn Badgley) join forces to track down an MIA Juliet (guest star Katie Cassidy). Chuck (Ed Westwick) begins to suspect Lily (Kelly Rutherford) isn’t telling him the full truth. Kevin Zegers guest stars as Damien. Blake Lively, Chace Crawford and Matthew Settle also star. Joe Lazarov directed the episode written by Stephanie Savage and Amanda Lasher.

4×12 The Kids Are Not All Right

Michael Boatman (“The Good Wife”) and Tika Sumpter (“One Life to Live”) guest star

A former associate of Chuck’s (Ed Westwick) father, Russell Thorpe (Boatman) – along with his daughter Raina (Sumpter) – returns to Manhattan with some unfinished business for our Upper East Siders. Serena (Blake Lively) and Chuck join forces against Lily (Kelly Rutherford). Blair (Leighton Meester) realizes that her mother, Eleanor (guest star Margaret Colin), may be her key to becoming a future CEO. Nate (Chace Crawford) worries that his father, The Captain (guest star Sam Robards), is having a little too much fun and not taking his parole seriously. Penn Badgley and Matthew Settle also star. Allan Kroeker directed the episode written by K.J. Steinberg.

4×13 Damien Darko

Blair vs. Dan

Blair (Leighton Meester) is ecstatic to land an internship at W Magazine, but the thrill quickly fades when she finds out that Dan (Penn Badgley) has secured one of the coveted positions as well. Chuck (Ed Westwick) may have finally met his match with Russell Thorpe (guest star Michael Boatman) – and his daughter Raina (guest star Tika Sumpter) – back on the Upper East Side. Nate (Chace Crawford) receives alarming news about his father’s (guest star Sam Robards) business prospects. Blake Lively, Kelly Rutherford and Matthew Settle also star. Jeremiah Chechik directed the episode written by Leila Gerstein.

4×14 Panic Roommate

Florence and The Machine performs – Andrew McCarthy directs

Blair (Leighton Meester) enlists Nate’s (Chace Crawford) help to win over her high-strung boss, Epperly (guest star Caitlin Fitzgerald), at W Magazine. Damien (guest star Kevin Zegers) stirs up more drama on the Upper East Side. Chuck (Ed Westwick) finds himself torn between business and pleasure. Florence and the Machine performs an acoustic version of “Cosmic Love.� Blake Lively, Penn Badgley, Kelly Rutherford and Matthew Settle also star. Andrew McCarthy directed the episode written by Jake Coburn.

4×15 It-Girl Happened One Night

Chuck fights to save Bass Industries – Michael Boatm (“Spin City”) & Tika Sumpter (“One Life to Live”) guest star

With Russell Thorpe (Boatman) poised for a takeover attempt of Bass Industries, Chuck (Ed Westwick) makes one last-ditch effort to save his family’s company. Blair (Leighton Meester) is given a challenging assignment at W Magazine with the promise of a possible promotion. Serena (Blake Lively) struggles with her feelings for Ben (guest star David Call). Penn Badgley, Chace Crawford, Kelly Rutherford and Matthew Settle also star. Bart Wenrich directed the episode written by Alex McNally.

4×16 While You Weren’t Sleeping

Happy 18th Birthday, Eric!

It wouldn’t be a proper Upper East Side party without some major Gossip Girl drama, and for Eric’s (Connor Paolo) 18th birthday celebration there is plenty to go around. Blair (Leighton Meester) decides to speed up the time table on her career path to becoming a powerful woman…. but ultimately stretches herself too thin. Serena (Blake Lively) is forced to choose between her family and Ben (guest star David Call). Chuck (Ed Westwick) and Lily’s (Kelly Rutherford) relationship remains icy in the aftermath of Lily’s betrayal. Penn Badgley, Chace Crawford, Kelly Rutherford and Matthew Settle also star. Norman Buckley directed the episode written by Sara Goodman.

4×17 Empire Of The Son

Billy Baldwin returns

Ben’s (guest star David Call) mother (guest star Marsha Dietlein Bennett) comes to town, forcing issues to the surface between Ben and Serena (Blake Lively). Russell Thorpe (guest star Michael Boatman) is determined to destroy Chuck’s (Ed Westwick) family legacy, but he risks alienating his daughter, Raina (guest star Tika Sumpter), in the process. Billy Baldwin returns as William van der Woodsen, Lily’s ex-husband and Serena and Eric’s father. Leighton Meester, Penn Badgley, Chace Crawford, Jessica Szohr and Matthew Settle also star. David Warren directed the episode written by Robby Hull.

4×18 The Kids Stay in the Picture

Gossip Girl returns with five fabulous final episodes for Season Four

As Lily (Kelly Rutherford) awaits the consequences of her decision, William van der Woodsen (guest star Billy Baldwin), CeCe (guest star Caroline Lagerfelt) and Lily’s sister, Carol (guest star Sheila Kelley), come into town to support her and be part of a Taschen photo shoot on “modern royaltyâ€� in which the Rhodes family is participating. Unbeknownst to Carol, who has always chosen to keep her daughter Charlie (guest star Kaylee DeFer) far away from the Upper East Side, Charlie has followed her to New York to meet Serena (Blake Lively) and the rest of the family. Blair (Leighton Meester) has an epiphany about her future, and grapples with the knowledge of whom she’s destined to be with. Penn Badgley, Chace Crawford, Ed Westwick, Jessica Szohr and Matthew Settle also star… J. Miller Tobin directed the episode written by Jessica Queller.

4×19 Petty in Pink

Serena is suspicious of Dan and Blair

Serena (Blake Lively) enlists Charlie (guest star Kaylee DeFer) to go undercover Gossip Girl-style to determine why Dan (Penn Badgley) and Blair (Leighton Meester) are spending so much time together, and what role an unexpected visitor is playing in their lives. With Nate’s (Chace Crawford) help, Raina (guest star Tika Sumpter) decides to go on a search for her long-lost mother. Chuck’s (Ed Westwick) hopes about his legacy are dashed with the reveal of devastating information from the past. Jessica Szohr, Kelly Rutherford and Matthew Settle also star. Liz Friedlander directed the episode written by Amanda Lasher.

4×20 The Princesses and the Frog

It’s war between Serena and Blair

Blair’s (Leighton Meester) dreams appear to be coming true, but Serena (Blake Lively) threatens to jeopardize it all by dredging up Blair’s past. Charlie (guest star Kaylee DeFer) befriends Vanessa (Jessica Szohr), who may or may not have a hidden agenda. Nate (Chace Crawford) is torn between his relationship with Raina (guest star Tika Sumpter) and a truth he must keep hidden out of loyalty to Chuck (Ed Westwick). Kelly Rutherford and Matthew Settle also star. Andrew McCarthy directed the episode written by Leila Gerstein.

4×21 Shattered Bass

Jack Bass (Guest star Desmond Harrington) returns to the Upper East Side

Charlie (guest star Kaylee DeFer) is finally starting to feel less like a fish-out-of-water with Serena (Blake Lively) and her friends, but complications present themselves when Charlie is invited to attend the Constance Billard alumni fundraiser. On the road to “happily ever after,� Blair (Leighton Meester) finds herself torn between the men in her life. Jack Bass’ (guest star Desmond Harrington) return to the Upper East Side sets off a chain of events that could end up destroying Chuck (Ed Westwick) and those closest to him. Jessica Szohr, Kelly Rutherford and Matthew Settle also star. Allison Liddi-Brown directed the episode written by Sara Goodman.

4×22 The Wrong Goodbye

Will Blair choose her Prince or her Dark Knight?

Season four wraps up with an explosive finale, including the return of Georgina Sparks (guest star Michelle Trachtenberg)and Constance Billard mean girls Kati and Is (guest stars Nan Zhang and Nicole Fiscella), a cameo by “Gossip Girl� author Cecily von Ziegesar, a performance by Airborne Toxic Event and, oh yeah, a few very juicy cliffhangers. Blake Lively, Leighton Meester, Penn Badgley, Chace Crawford, Ed Westwick, Jessica Szohr, Kelly Rutherford and Matthew Settle star. Patrick Norris directed the episode written by executive producer Joshua Safran.