1x15 - Gossip Girl

Serena's world descends into chaos when a former friend, the evil Georgina Sparks returns to town. Nate connects with the last person he expected, Vanessa. Blair hatches a plan to sabotage her biggest rival, Nelly Yuki. Meanwhile Serena goes out with Georgina, but things get so bad that Serena thinks someone spiked her non-alcoholic drink. Jenny develops a crush on a dog-walker, Asher Hornsby, who might be her ticket to permanent popularity.