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.

During the first day of school at Constance Billard, Jenny takes her place as the new Queen Bee. However, Blair gets in her way. Lily returns home to find that things are not as they were when she left them with Rufus. At NYU, Olivia Burke, an actress, enrolls and is assigned to be Vanessa's roommate.

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.