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.

Nate suspects that Juliet is keeping a big secret from him and decides to confront her. Blair schemes to undermine Chuck's newfound happiness. Dan finds himself torn between his feelings for Serena and Vanessa.

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.

Chuck and Blair decide it’s in both their best interests to put the past behind them and end their vindictive games. Nate confronts Juliet after discovering a secret she has been keeping from everyone. Dan and Nate realize they both still have feelings for Serena.

Chuck hosts a "Saints and Sinners" masquerade party at the Empire Hotel. At the party, Dan and Nate don't know what to make of Serena's strange behavior and mixed messages. Blair sets her sights on becoming the new face of Anne Archibald's foundation for girls, but Anne is concerned that Blair's friendship with Chuck Bass may be problematic.

Chuck, Serena, Blair, Dan, Jenny and Eric find themselves faced with a crisis when a member of one of their families is hospitalized. Meanwhile, Nate attempts to help his parents, The Captain and Anne, put their complicated past behind them and reconcile.

Blair and Dan join forces to find Juliet. Serena expounds her boarding school experiences to her therapist and discovers the truth behind Juliet's vendetta against her. Meanwhile Chuck suspects Lily has not told him the full truth.

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.

Blair is ecstatic to land an internship at W Magazine, but the thrill quickly fades when she finds out that Dan has secured one of the coveted positions as well. Chuck may have finally met his match with Russell Thorpe – and his daughter Raina – back on the Upper East Side. Nate receives alarming news about his father’s business prospects.

Blair enlists Nate’s help to win over her high-strung boss, Epperly, at W Magazine. Damien stirs up more drama on the Upper East Side. Chuck finds himself torn between business and pleasure. Florence and the Machine performs an acoustic version of “Cosmic Love.”

With Russell Thorpe poised for a takeover attempt of Bass Industries, Chuck makes one last-ditch effort to save his family’s company. Blair is given a challenging assignment at W Magazine with the promise of a possible promotion. Serena struggles with her feelings for Ben.

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.

Ben’s mother comes to town, forcing issues to the surface between Ben and Serena. Russell Thorpe is determined to destroy Chuck’s family legacy, but he risks alienating his daughter, Raina, in the process. Billy Baldwin returns as William van der Woodsen, Lily’s ex-husband and Serena and Eric’s father.

As Lily awaits the consequences of her decision, William van der Woodsen, CeCe and Lily’s sister, Carol, come into town to support her and be part of a Taschen photo shoot on “modern royalty” in which the Rhodes family is participating. Unbeknownst to Carol, who has always chosen to keep her daughter Charlie far away from the Upper East Side, Charlie has followed her to New York to meet Serena and the rest of the family. Blair has an epiphany about her future, and grapples with the knowledge of whom she’s destined to be with.

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’s dreams appear to be coming true, but Serena threatens to jeopardize it all by dredging up Blair’s past. Charlie befriends Vanessa, who may or may not have a hidden agenda. Nate is torn between his relationship with Raina and a truth he must keep hidden out of loyalty to Chuck.

Charlie is finally starting to feel less like a fish-out-of-water with Serena 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 finds herself torn between the men in her life. Jack Bass return to the Upper East Side sets off a chain of events that could end up destroying Chuck and those closest to him.

The episode continues from the early events of the Constance Alumni event. Georgina Sparks turns up at the event looking for trouble. Serena and Vanessa reluctantly join forces to find Dan and Charlie, who does not take Dan's rejection of her well. Blair must make a choice between the men in her life when her life is in danger by Russell.