Season 1 - Episode 18

18 - Much 'I Do' About Nothing

Blair decides to take matters into her own hands and deal with Georgina Sparks (Michelle Trachtenberg); Lily prepares for her wedding day with Rufus on her mind; Serena finally tells Dan the truth about her past. After Serena tells Dan about what happened, they finally work things out.
Georgina's parents are tired of her antics and tell her that things won't be alright if she doesn't get her act together. Blair is there for support... or is she? The Sparks want to send their daughter to a boot camp for troubled girls. At the wedding, Bart, Lily, Chuck and Eric are all smiles. Rufus surprises Lily in the bridal chamber.

Season 1 - Episode 17

17 - Woman On The Verge

The episode starts off with Nate and Chuck being called to Blair's house since Serena is in trouble. It is still evident that the 3 of them are still feuding. Dan is equally worried about Serena as well but everyone refuses to tell him what happened and what is going on with Serena, who had a terrible night and is staying with Blair. Serena is forced to tell Dan that she cheated on him last night, while she didn't because she claims she couldn't risk Dan knowing about what really happened to her a year ago and the real reason she left. She explains the entire story to her friends that Georgina tried to film a sex tape of Serena and accidentally recorded someone dying. Meanwhile, Lily finds the tape and assumes the worst about her daughter.

Sarah (Georgina) becomes closer to Dan because she is angry at Serena for revealing the truth behind the events a year ago.

Meanwhile, Rufus is excited when his band is invited to perform at a Rolling Stone-sponsored concert, but Lily is the last person on earth he expects to see at the performance, especially since her wedding rehearsal dinner is the same night.

Season 1 - Episode 16

16 - All About My Brother

Blair and Jenny face off and each sends numerous of fake rumors to Gossip Girl, such as Jenny wading in a pool to collect the coins at the bottom. Meanwhile, Dan discovers Asher kissing another boy. Likewise, Eric tries to warn Jenny that Asher is not what he really looks like, but Jenny mistakes it for jealousy on Eric's part. When Dan confronts Asher about it, he denies it, and when Jenny joins them, he makes Dan seem like an over-protective brother. Jenny and Asher host their own high-society party, to which Blair is not invited.

Meanwhile, Serena believes that Georgina has left town, but is jolted back to reality when Georgina sends her a USB showing a clip of Georgina and a man. It is believed that will also show what Serena did before leaving, but Serena closes it before anything is revealed. Dan and "Sarah", who is really Georgina, grow closer.

When Dan tips off Gossip Girl that Asher is gay, Jenny becomes irritated, believing it as another rumor that Blair posted. Her relationship with her father becomes strained, and he finds parenting advice in Lily van der Woodsen. Jenny finds out that Asher has been using her to conceal up his sexuality. Blair steals Asher's cellphone to truly find out his sexuality, and sets the cellphone to forward all his texts and photos to her cellphone.

Georgina stays for dinner with the van der Woodsens, much to Serena's displeasure. After strained conversation, Georgina reveals that Eric, too, is gay. After Lily breaks down from realization, Eric tells Serena that he was the boy Asher was seen kissing by Dan. At the party, Blair crashes and walks straight to Asher and says that, since the other boy she realizes is Eric, whom she cares about, she will not tell Gossip Girl that he is gay, but is warning she knows. Eric comes up with her, and when Asher still does not tell, Eric walks away, telling Blair to "send it". Blair then sends all the texts to Gossip Girl.

Meanwhile, when Serena finds out that Sarah is really Georgina, she tells Dan not to trust her. He, thinking she is jealous, becomes frustrated because she has become distant. Serena talks to Georgina separately, Georgina states that she is only doing this because she wants things to go back to the way things used to be. Serena still rejects her, and Dan, Vanessa, and Georgina leave Serena by herself. That night, Serena,desperate, goes to Blair's house, where after Serena becomes more and more desperate, she reveals that she had killed someone.

Season 1 - Episode 15

15 - Desperately Seeking Serena

It's SAT time, and Georgina Sparks (Michelle Trachtenberg), Serena's former partner in all things bad, returns to Manhattan. They go out to a bar one night and things go haywire. The next night, they decide to have a one hour dinner, no alcohol. However, Georgina spikes Serena's drink, and she ends up missing another study night with Dan. Nate finds romance with Vanessa, the last person he would expect. Jenny meets a guy who could be her ticket to permanent popularity, but Rufus on the other hand, grounds her for the Valentino incident. Dan and Blair discover Vanessa and Nate are spending time together.
Meanwhile Blair is trying to bring down Nelly Yuki, one of the smartest girls at Constance, so that she will wipe out the competition for Yale. She does so by keeping Nelly off focus by having her ex-boyfriend mess with her feelings so that she will screw up her SAT's.

Season 1 - Episode 14

14 - The Blair Bitch Project

Blair hesitantly returns to school after being dethroned as Queen Bee. Serena struggles to adjust to living with her future stepbrother, Chuck, and receives disturbing packages from an unknown sender. Jenny's drive to be popular hits a high. Her birthday is coming up, and she feels too ashamed of being middle-class so she steal's Hazel's mother's red Valentino dress.