Credit: Courtesy of Gossip Girl/CW

It's Serena versus Blair once again on Monday's episode of Gossip Girl, and this time, Serena's doing all the scheming! Upon witnessing a kiss between Blair and Dan via Gossip Girl, Serena (at right in a Rachel Gilbert shirt and Vince jeggings) is determined to sabotage Blair and her royal love interest, Louis. In other Upper East Side news, newcomer Charlie befriends Vanessa who may or may not have a hidden scheme of her own. Tune in Monday, May 2nd at 9/8c to get your weekly dose of drama and click through the gallery to see more looks from the episode!