Desperately seeking Serena

Dan, Blair, and Serena are studying extremely hard from the SAT exam. Rufus wants to walk Jenny to school, but Jenny is horrified by the idea. She leaves abruptly. Blair is jealous of Nelly Yuki because she has her sights on Yale, which means that Blair might not have a chance if she gets in.

Serena finds an old bad friend: Georgina. Serena used to take drugs and get drunk with her. Her past is coming to the present and she's "different" now. But a relationship like this are dangerous, and Serena isn't hearing his mind, she falls into Georgina's hands and make stupid things all over again.

Serena tells Chuck that she needs his help by saying she got intoxicated and she wouldn't go to her date with Dan. The next day Dan's realises something was wrong and asked Serena where's is girlfriend. 

Dan is studying. He tells Jenny that he is distracted by Serena. Jenny finishes all her homework and Rufus pulls out a sewing machine for her. She is so happy, but when Rufus says she's still grounded. Jenny mentions that she wants to meet with a guy tomorrow. He doesn't want her to date, so she gets angry and goes to her room. At Blair's spa treatment, Nelly Yuki is relaxed. Her ex-boyfriend, Todd, shows up. Nelly is happy to see him. He wants to talk to her. Nelly is happy and thanks Blair. Unfortunately, Nelly doesn't know Blair's plan. Nate and Vanessa are walking together and having a good time. He asks Vanessa why she takes SATs practice tests without the intention of taking the real SATs. They continue to have a good time until they get to Vanessa's workplace. They share their first kiss here. Serena and Georgina are having dinner. To Serena's surprise, Georgina refuses a cocktail. Serena tells her more about Dan and their relationship. Serena goes to call Dan. Georgina slips a drug into Serena's soda. They drink to the new Serena.

The next morning, Serena wakes up wondering where she is. Georgina comes in and Serena panics about the SATs. She calls Chuck and asks him to help out and try to keep the doors open for her. Nate meets Vanessa at her restaurant. Nate wants to take her somewhere. Vanessa decides to go along with him. Rufus and Jenny are eating breakfast. She is still angry at him. Jenny asks again to let her go. Rufus makes her cancel with Asher. Nate takes Vanessa to the SATs. He convinces her to take it to have options. Nelly Yuki shows up and Blair asks her how her night was. Todd doesn't want to get back together and Nelly stayed up all night crying. Blair takes the batteries from her calculator. Blair asks Dan where Serena is, but he doesn't know. Dan starts to leave Serena a voicemail. He then sees a girl claim she is Serena van der Woodsen.

In the end of the episode Serena tells everyone that Georgina's back.

The Blair bitch project

Serena is trying to adjust to living with Chuck. On the way to school, Serena is trying to tell Blair that her scandal is old news.
Nate tries to warn Jenny that the clique will turn on her as soon as they get a chance. Running with the popular crowd is a dangerous game, and if they can turn on Blair they can turn on anyone. On the steps, S tries to give B a pep talk now that the active yogurt cultures have washed away.  Serena tries to tell her that she'll recover more quickly if she's nice to people, which is an attitude B will test out when she attends Jenny's big birthday bash.  The entirety of B's old crew will be there, so that should prove awkward.
Nate goes to Dan with the news about J's $8000 request, while Jenny desperately tries to get the Valentino dress off.  The gang walks in while she's still wearing the little red number, and B couldn't be happier at this turn of events.  The gang, realizing that Jenny is a klepto, abandons her and follows Blair to Butter.  Well, that didn't take long.

When Rufus demands to know where she got the dress, Jenny breaks down in tears.  She's upset at constantly having to brown bag it while her friends go and eat at the hottest restaurants in the city. Meanwhile, Serena is distressed by the fact that Eric is hanging out with Chuck.  She's also freaked out by getting a small package of cocaine in the mail.  Secret Santa strikes again.

Serena takes the cocaine to Chuck and blames him for sending it, but he's busy wearing a weird shirt with sharks on it.  He's also moving back to his suite.  Bart has kicked him out for bad behavior.  At Butter, B waits for the gang to arrive, slightly worried that they're all going to ditch her again.  This time they show up and immediately boost B's social profile.  Is she back on top already, or is Little J going to demand a rematch?

Dan wants to take Jenny out for ice cream, but Rufus doesn't want to let her out of the house.  That's too bad for Rufus, because J has already left without permission.  She goes to see Nate and asks him to take her to Butter.  They make a hot entrance, sit down at B's table, and the gang, impressed by J's ability to land Mr. Archibald, immediately forgive her for the Valentino debacle.  Well, it looks like Jenny has some fight left in her after all.

Serena's next mysterious package comes in the form of a letter from Georgina Sparks.  G is the one who sent all the goodies, and it looks like she'll be in town causing trouble next week.  Serena's past is coming back to haunt her in a major way.

The thin line between Chuck and Nate

Gossip Girl posts a picture of Serena looking at pregnancy tests, everyone thinks that she must be pregnant. Jenny, Dan, and Rufus see the news online, and Dan worries about what's the right thing to say. But the real thing is that the pregnancy test isn't for her, it's for Blair. Blair refuses to make the test because she's so happy cause her life is doing well, including that she came back with Nate. 
Serena tells Dan the truth about Blair's situation in the dinner with the Humphrey's family. Dan tells Serena that even though Chuck is a totally jerk, he deserves to know what's going on.

She confronts Blair over her dishonesty. Making a point by saying she exposed herself by getting the test for her.
Blair finally makes the test and later calls Serena to tell her that she's not pregnant.
Everyone see the news about Blair when school lets out. Nate initially believes that it must be a lie, but Jenny, who overheard Serena's conversation with Dan the previous night, tells him the truth. Nate gets into a fight with Chuck over the whole thing, then tells Blair he wants nothing to do with her. She is quickly overthrown as the queen bee, with Jenny joining the popular group. Serena asks Dan if he told Jenny anything relating to Blair, so he says he wouldn't do something like that to her because he loves her.
Blair is then shown going to see Chuck at a bar. She explains that he is the only person that wants to be around her now, and Chuck replies that he is no longer interested in her. Overcome by her recent troubles, Blair begs her mother to let her spend a semester in France. Serena goes to see Dan, and they both finally profess their love to each other. But their happiness is cut short when Serena discovers that Blair is going away. She races to see Blair before she gets on the plane, and convinces her to stay and fight for her life.