Gossip Girl (2007): Season 4, Episode 5

4 - 5: Goodbye, Columbia

Juliet sends a Gossip Girl blast that starts a very damaging rumor about Serena, saying she has an STD. Vanessa becomes worried that Dan and Serena may have slept together and turns to Juliet to help her get answers. After checking Serena's phone, Vanessa discovers than Dan and Serena did not sleep together. Vanessa then becomes collateral damage in Juliet's vendetta against Serena when she frames her for sending an e-mail from Serena's phone to her English professor offering sex for grades. Elsewhere, Chuck threatens Blair's chances to become the powerful businesswoman Martha's (guest star Marilyne Barrett) new assistant.