The privileged prep school teens learn that Serena van der Woodsen is back in town.

In the wake of the scandalous Kiss on the Lips party, Serena receives an icy cold reception from Blair.

Blair uncovers scandalous information about Serena; Dan sets his sights on impressing the Dartmouth representative.

Blair is thrilled when her mother, Eleanor, chooses her to be the new face of her clothing line; Serena and Dan are reminded once again that they come from two very different worlds; Nate and Chuck indulge in a boys' weekend to blow off steam after Ivy Week.

Dan makes elaborate plans to impress Serena on their first official date; Jenny is invited to the infamous Blair Waldorf sleepover and finds herself in a high-stakes game of truth or dare; Lily discovers Eric missing from his treatment center, and seeks help from her ex-boyfriend, Rufus.

Dan is torn between two girls when his childhood friend Vanessa returns home and declares her feelings for him

Serena and Dan finally acknowledge they are crazy about each other; Jenny discovers a secret about her parents; Blair is once again devastated by Nate's actions.

Blair puts on a happy face for her 17th birthday party and attempts to hide the truth from her friends.

When Dan finds out that Serena and her family are celebrating Thanksgiving alone, he naively invites them to spend the holiday with his family.

As 'Gossip Girl' posts news of the annual Cotillion Ball to take place on the approaching weekend, Blair decides not to go with Nate, but she finds herself being featured in The New York Times and is enjoying her secret affair with Chuck. Serena decides not to go either, so her grandmother, CeCe, shows up to change her mind. Meanwhile, Jenny volunteers for the ball and Lily takes her under her wing. But the night of The Cotillion is the night of Alison's first art opening, and Rufus and Alison tell Jenny that she cannot attend the ball. Jenny decides to defy them both by secretly attending the dance anyway. Refreshed by Blair's newly buoyant attitude, Nate asks her to the Cotillion and she accepts, which makes Chuck jealous. CeCe tells Lily and Serena that she is sick with lung cancer and her last dying wish is to see Serena go to the ball, and she wants Serena to go with the wealthy Carter Baizen. The snobbish CeCe takes an instant dislike to Dan and she approaches Rufus with an offer pay him to convince Dan not to go with Serena. Dan learns of this and tells Serena that he does not think very highly of CeCe by telling Serena about how CeCe tried to bribe his father to persuade him not to attend. Surprisingly, the skeptic Serena refuses to believe Dan that her compassionate grandmother is a crafty snob, and she ends up going to the ball with Carter... both her and Dan having fallen right into CeCe's ploy. Also, Chuck manipulates Nate into thinking Carter is having an affair with Blair to provoke a fight with him.

Blair's father comes home for the holidays with an unexpected guest; Jenny and Vanessa help Serena plan the best Christmas surprise ever for Dan.

The gang breaks into the school swimming pool, but when one of them nearly drowns, the school threatens to expel the ones who broke-in.

Gossip Girl takes pleasure in reporting that Serena has been spotted buying a pregnancy test, and word spreads like wildfire.

Blair returns to school after losing Queen Bee status; Serena's not fond of living with her future stepbrother, Chuck.

Serena's world is turned upside down when her former partner in crime, Georgina Sparks, returns to Manhattan to stir up trouble.

Blair and Jenny escalate their "popularity war" by spreading scandalous rumors about each other through Gossip Girl.

Georgina reveals the true reason that Serena fled Manhattan for boarding school, and Serena quickly falls back into her old habits.

With Serena's reputation on the line, Blair takes matters into her own hands to deal with manipulative Georgina.