G really wants to hang out, but S is ignoring her. While Dan and Serena may be having trouble, everything is great between Lily (Kelly Rutherford) and Bart Bass.
Dan learns learn that Serena didn't come home the night before, and then he runs into "Sarah" outside of S' place. They get to talking, and Dan gets a call from Serena. Except it isn't actually S.
It's a bartender letting Dan know that Serena left her phone there, right around the time she left with three guys. Dan was the first number on her speed dial, at least.
Chuck and Nate (Chace Crawford) are still acting like a married couple on the rocks. They arrive at Blair's place, thinking it's a ploy to get them talking again. B puts this theory to rest when she arrives with an unconscious, drunk Serena.
Blair forces Serena into the shower. After S spilled her secret to Blair, she went out and got wasted at the local bar. Chuck wants to know the secret, but B is too good a friend to spill the beans.
Meanwhile, Dan shows up again at Serena's, where Lily tells him that he may want to check Blair's place for his long lost girlfriend.
When Dan arrives at Blair's, B tells him that S has no desire to see him. Serena comes down a moment later, and Dan demands to know what's up.
He wants to know what guys she went home with the night before, but she doesn't seem to remember what happened. He asks if she slept with someone else last night, and she says yes.
Dan leaves, devastated, but Sarah gives him a call and asks if he wants to talk about his troubles. Not surprisingly he plays into it.
Serena explains that she intentionally lied to Dan, because she'd rather he think she slept with someone else than know what she really did. Then the gang insists on knowing her secret. Serena spills the story.
At the same wedding where Serena slept with Nate, she went to G's place at the end of the night, where G had the secret video camera set up. Some mystery guy was putting the moves on Serena.
To distract him from wanting to have sex with her, Serena suggested that they do a couple lines of coke first instead. The guy did one, then overdosed.
Serena called 911, but Georgina insisted they make a break for it, leaving Serena to watch from across the street as paramedics wheeled out the dead body.
Not only do Blair (Leighton Meester), Nate, and Chuck now know, but Lily - after getting a call from B's maid Dorota telling her Serena is in bad shape - Lily checks her room and finds the sex tape.
At the party to celebrate Lily and Bart's wedding, Lily confronts Serena about it. Lily threatens to send her away, which causes Serena to break down. B confronts Lily and tells her that S has a secret.
At Rufus' rock concert, Vanessa figures out Georgina is up to know good when Nate calls her and tells her that "Sarah" is alias used by Georgina.
Lily takes Serena to visit the parents of the dead guy. It turns out he was an addict for 10 years before meeting Serena, so he was pretty much doomed anyway. They don't blame Serena (Blake Lively) for what happened. With it off her chest, she now feels she can tell Dan.
Blair and Chuck go to confront Georgina. Before they arrive, Vanessa tells G that she knows what she's up to. G initially tries to deny it, but then makes up an elaborate story when Dan (Penn Badgley) arrives.
After making up an elaborate reason for the name change, she tells Dan that she's falling for him. While Dan steps out for a moment, G calls Serena and tells her that all bets are off. Georgina is going to seek revenge by doing all sorts of awful, sexy things with Dan.
She doesn't waste any time, and starts making out with him as soon as she hangs up. Elswhere, Rufus sees Lily while he's on stage, then chases after her and refuses to let her leave. They embrace in a passionate kiss, meaning her upcoming wedding to Bart may be a question mark after all.
(Source: TV Fanatic)