Lily and Rufus move up their wedding day, but someone or something will come between them. Can they overcome this and finally get married? Chuck uncovers Carter’s secret. Georgina traps Dan and Vanessa into one of her schemes. Blair suspect something not good about Bree and shares her concerns with Nate.
It’s Jenny’s first day of school at Constance Billard which means it’s her time to take her place as the new Queen Bee. But Blair wants to take her spotlight when she is needed back at Constance. Lily returns home to find that everything is different now. Meanwhile, a famous movie actress, Olivia Burke, enrolls in NYU and as Vanessa’s new roomate who wants to have a normal college life. Tyra Banks guest stars as Ursula, a co-star in Olivia’s movie and Serena’s new friend.
It’s a face-off between Chuck and Blair when they both want to bid on the same item at Sotheby’s. Meanwhile, Serena suspects that Carter may have return to his old habits, while Georgina takes an interest in Dan, and Vanessa suspect something is not right with Scott.
Blair ends up with Georgina as as her roommate in the dorms at NYU. While Serena and Chuck come to blows, so she joins forces with Chuck’s enemy, Carter. Nate and Bree try to take their relationship up a gear despite the animosity between their families.
As the summer ends, Blair and Chuck are madly in love and adjusting to their new “in a relationship” status, breaking all traditional rules of dating as would be expected. Serena returns from her European adventure with many secrets to hide and a complicated relationship with Carter Baizen. Nate returns from his travels with a mysterious brunette, Bree Buckley. Rufus, Dan and Jenny spent the summer in the Hamptons, adjusting to the Van Der Woodsen’s glamorous lifestyle much faster than any of them expected.