It's the day right after the Kiss on the Lips party and Serena receives a cold reception from her former best friend Blair. Blair reveals that she knows that Serena and Nate slept together, before Serena mysteriously went to boarding school. Then Serena decides to take Dan to Chuck's fundraiser brunch at The Palace. Meanwhile little Jenny asks Blair for advice, and Blair realizes that she maybe gains something by allowing Jenny into her inner circle.

Chuck finds himself once again at odds with his uncle, Jack Bass. Eleanor 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 big turn for the worse when Jenny learns that Agnes will be one of the models.

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

On her first day at Columbia, Blair attempts to gain membership into an ultra-exclusive social club, Hamilton House .... but she’s in for a few big surprises. Serena begins to suspect that Juliet is intentionally sabotaging Serena’s life and that it may have something to do with Nate. Rufus is worried about Dan and decides to take matters into his own hands.

An anonymous Gossip Girl blast starts a very damaging rumor about one of Columbia's new students, Serena. On her path to greatness, Blair decides to take a class with a powerful businesswoman, Martha, who is guest-lecturing at Columbia, but a mysterious fellow student thwarts her plans to secure the prized position as Martha's assistant.

Although Blair made it perfectly clear that Little J was no longer welcome in Manhattan after what happened with Chuck, Jenny is tempted by a once-in-a-lifetime opportunity to meet Tim Gunn, which could be a game changer for her future. Meanwhile, Serena discovers something about her new boyfriend, Colin, that may put an end to their relationship just as it was getting good.

Blair is caught off-guard – and not in a good way – by a surprise guest at her birthday party. Having had enough of Chuck and Blair’s games, Serena and Nate decide to plan an intervention.

A former associate of Chuck’s father, Russell Thorpe – along with his daughter Raina – returns to Manhattan with some unfinished business for our Upper East Siders. Serena and Chuck join forces against Lily. Blair realizes that her mother, Eleanor, may be her key to becoming a future CEO. Nate worries that his father, The Captain, is having a little too much fun and not taking his parole seriously.

It wouldn’t be a proper Upper East Side party without some major Gossip Girl drama, and for Eric’s 18th birthday celebration there is plenty to go around. Blair decides to speed up the time table on her career path to becoming a powerful woman.... but ultimately stretches herself too thin. Serena is forced to choose between her family and Ben. Chuck and Lily’s relationship remains icy in the aftermath of Lily’s betrayal.

Serena enlists Charlie to go undercover Gossip Girl-style to determine why Dan and Blair are spending so much time together, and what role an unexpected visitor is playing in their lives. With Nate’s help, Raina decides to go on a search for her long-lost mother. Chuck’s hopes about his legacy are dashed with the reveal of devastating information from the past.

Blair makes all of her former minions and Charlie compete to secure the coveted bridesmaid spots in her upcoming royal wedding. Nate is tired of keeping his relationship with Diana a secret, so he decides to use Charlie to make Diana jealous. Serena's boss is determined to acquire the film rights to Dan's book, so Serena must put her personal feelings about Dan and the book aside in order to close the deal.

Serena is hard at work planning a dream bridal shower for Blair, but it should come as no surprise that Serena has to plant some false information about the shower in order to keep Blair from finding out all the details. Chuck and Dan decide to spend the day together to distract themselves from the fact that they didn’t make the invite list for Blair’s shower. Nate and Serena find a silver bullet in Diana’s war against Gossip Girl, but struggle about whether to use it or not.

Blair prepares to celebrate her upcoming royal wedding with a bachelorette party, but others scheme behind her back to make this a night to remember. After discovering the truth behind Chuck and Blair’s car accident, Nate joins forces with a surprising ally to gather the evidence. Serena and Dan pretend to be dating again to protect someone close to them.

The much-anticipated 100th episode will open with a musical dream sequence featuring Serena, Blair and all the men in their lives. Also, while Chuck wrestles with the reality that Blair is about to walk down the aisle with Prince Louis, the return of Georgina Sparks might make the royal affair a royal disaster.

When Gossip Girl goes after Blair as she’s never done before, Serena admits she may have unintentionally played an important role in Blair’s latest nightmare. Meanwhile, Nate invites Lola to move in with him, and Lily must make a big decision about the future of her marriage. Finally, by episode’s end, Blair will make a choice between the two men in her life…will it be Chuck or will it be Dan?

Trying to prove herself in adult society, Serena hosts the Central Park Conservancy’s big gala, of which she is now the newest Board Member, and she and Nate both learn something shocking about their significant others. Blair prepares to debut her new fashion line, but a rival from her past holds the key to her future. With the help of Georgina, Dan lands some meetings with publishers, but he must decide if he is willing to sacrifice his integrity in order to get his work published. Meanwhile, Chuck tries to persuade Amira to help him look into his father’s past, even if it means jeopardizing Lily and Bart’s relationship.

After Eleanor gives Blair an ultimatum, Blair is even more determined to remedy Waldorf Designs’ problems by making a splash with a dress at the upcoming Cotillion, but a shocking revelation at the ball affects everyone. Serena becomes worried about Steven’s attitude toward her, but after some investigating she discovers the surprising reason why. Chuck finds an unlikely ally as he tries to drive a wedge between Bart and Lily’s relationship to help expose his father’s secret. Meanwhile, Dan publishes another article, but the effect is just the opposite of what he was hoping for.