Blair gets excited when her mother, Eleanor, chooses her to be the new face of her clothing line. However, Blair's happiness turns quickly into feelings of betrayal and jealousy when Serena takes her spotlight and Blair finds herself back in Serena's shadow. Meanwhile, Serena and Dan remember once again that they come from two very different worlds. Also, Nate and Chuck do a boys weekend to blow off steam after Ivy Week ends.

Serena's grandmother announces that Serena has to go to Debutante Ball. However, Dan is not what CeCe wants as an escort for Serena, and she makes her opinion heard loud and clear, causing a rift between Serena and Dan. Although they are officially broken up, Nate asks Blair to go to the ball with him. A jealous Nate begins to suspect that Blair is seeing someone else. Jenny finds herself having to make the decision of either attending her mother's art opening or following her dreams to the Debutante Ball, even though her parents don't want her to go.

The Constance Billard and St. Jude seniors have the production of "The Age of Innocence". Serena has a crush on the play's director, Julian, and enlists Vanessa's knowledge of theater to help her get the guy's attention. Blair receives bad news about her future that leads her on a witch hunt for the person responsible. Dan and Rachel agree to stay away from each other in the aftermath of being discovered as more than teacher and student, but find it impossible to keep that promise. Chuck find help on an unlikely friend, Carter Baizen.

Devastated by the turn her life has taken, Blair opts for a wild lifestyle instead of her perfect Waldorf life, causing Chuck and Serena to become concerned. Vanessa tries to convince Nate that he needs to move on after his mother's family, the Vanderbilts, abandoned him and his mother. Trying to be honest with each other, Lily and Rufus both put together their lists of past relationships.

Gossip Girl decides to liven things up at the Constance Billard and St. Jude’s graduation 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 challenge Jenny to throw her hat in the ring to succeed Blair as Queen Bee next year. Lily and Rufus struggle to repair their relationship after Lily’s betrayal. As for the cliffhangers, Blair and Chuck finally… and Serena is shocked by… and Georgina decides to… and Dan, Nate, and Vanessa unknowingly…. Jenny and Eric do something they might end up regretting.

As summer draws to an end, Blair and Chuck continue to adjust to being in a relationship with one another. Serena returns from Europe with new secrets to hide and a new relationship with Carter Baizen. Nate also returns from vacationing and brings home a mysterious girl, Bree Buckley. Meanwhile, Rufus, Dan and Jenny spend the summer in the Hamptons and learn to adjust to the van der Woodsen's glamorous lifestyle

Blair, determined to have her Queen status at college, starts her first day at NYU along with Dan and Vanessa. However, Georgina, who was assigned as Blair's roommate, sets out to ensure that she does not retain her title. Serena gets ready to move into her dorm at Brown, but has a fight with Chuck before hand. This leads her to search out Chuck's enemy, Carter, to help her get even with him. Meanwhile, Nate and Bree's relationship continues to grow despite the tension their relationship could cause between their families.

Blair and Chuck face-off when the both set their sights on an item up for bid at Sotheby's. Serena begins to think that Carter may have returned to his old habits, Georgina becomes interested in Dan, and Vanessa thinks that something is wrong with Scott.

Lily and Rufus decide to move up their wedding to the next day, but will someone or something come between them before they become man and wife? Chuck discovers a secret that Carter has been keeping from Serena. Dan and Vanessa are pulled into one of Georgina’s schemes. Blair is suspect of Bree and shares her concerns with Nate.

Vanessa, hoping to finally win her mother Gabriela’s approval, desperately vies with Blair for the honor of delivering the freshman toast at NYU, but at what price? Dan invites Olivia 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.

Chuck offers to throw a wedding for a very pregnant Dorota who insists that she and Vanya 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’s secretly meeting up with Carter Baizen. Rufus discovers that Lily has been lying to him about her whereabouts.