"It girl" Serena van der Woodsen has returned to Manhattan after a mysterious and self-imposed exile to boarding school. Serena's best friend, Blair Waldorf, has conflicted feelings about her friend's return since she has enjoyed being the Queen Bee during Serena's absence and might not be ready to relinquish her new position on the social ladder, not to mention the fact that she has always suspected there may be unspoken feelings between Serena and her longtime boyfriend, Nate.

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.

It's Ivy week for the Upper East Side teens of Constance Billiard and St. Jude's and the visiting representatives' arrival brings more than just college applications. Cut-throat rivalry is at its sharpest this week as the students compete for prestigious positions. Blair discovers a shocking but juicy secret about Serena and plots to drop the bomb at the best possible moment. Dan is sure that landing the coveted usher position with the Dartmouth rep will either make or break his future at the school. Unfortunately, it's Nate who nabs the position, despite total disinterest in the school. Meanwhile, Jenny gets closer to Serena's younger brother Eric and Rufus asks Lily for a favor.

Dan finds himself between two girls when his childhood friend, Vanessa, returns to N.Y. and declares her feelings for him, just as he and Serena are trying to figure out what they mean to each other. At the masked ball, Blair sends Nate on a scavenger hunt, but Nate is distracted by his feelings for Serena. Although Blair said that outsiders were not welcome to the party, a disguised Jenny and Dan sneak into the ball. Finally, Lily asks Rufus to accompany her to an Eleanor Waldorf event only to make Bart Bass jealous.

Serena and Dan finally accept that they are crazy about each other, despite that they come from polar opposite worlds. Chuck thinks of investing in a club trying to make his father Bart Bass proud of him. Nate confronts his father, about the drugs he found in his house but he denies having a problem. Jenny discovers a secret that her parents have been keeping from her. Finally, Blair is devastated by Nate's actions when Jenny reveals that Nate kissed her by accident thinking she was Serena.

Blair is feeling heartbroken and guilty by the current state of her relationship with Nate and her recent indiscretion. But she manages to put on a happy face for her 17th birthday party and attempts to hide her feelings from her friends. Hoping that Serena and Vanessa can bond, Dan takes Vanessa to Blair's birthday party. Jenny brings her mother home as a surprise, but Rufus isn't ready to forgive and forget. Finally, Nate's parents ask him to make a huge sacrifice to save his father's business.

Dan invites Serena and her family to spend the holiday with his family, creating an uncomfortable situation for Rufus and Lily. The children are unaware of their complicated romantic past. Meanwhile, Blair's freaks out when she learns that her father isn't coming home for Thanksgiving. Nate spends the holiday with his family, but their awkward dinner quickly goes from bad to worse.

Blair takes matters into her own hands to help Serena with the manipulative and evil Georgina Sparks. Lily, while keeping Rufus in her mind, prepares for her wedding with Bart Bass that is designed to be the Upper East Side's social event of the year. Serena finally tells Dan the whole truth about her past and they try to work things out after Dan has cheated on her, but will it be too late? An unexpected guest shows up at Lily and Bart's wedding. Georgina is sent somewhere where she can do no harm. Blair plans to go somewhere with Chuck.

It's Thanksgiving time and Blair is offended when her Mom's new man hijacks her Thanksgiving traditions. Lily attempts to strengthen the frail bond between Rufus and Jenny. Eric discovers a secret about Bart. Vanessa and Chuck help Nate deal with his father.

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.

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.

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.

After a run-in with an increasingly paranoid Bart, Blair grows alarmingly concerned for Chuck’s safety. However, feeling confident that his father will never hurt him, Chuck makes a deal that could change his life. Wanting to make things better for Chuck, Blair devises a plan with the help of Serena, Georgina and Sage to try and get what they need out of Bart. Meanwhile, Nate's financial dilemma finally lands him in a place that he never thought he would be.