After her initial plans to unseat Eva fail, Blair calls in for backup. She enlists Serena and Dan to dig into Eva's past online, and they learn that Eva was a prostitute! When Chuck finds out, he confronts Eva, they talk, and soon they're once again kissing in front of a furious Blair. So she tries a last-ditch, truly dirty effort by planting Chuck's passport in Eva's bag to convince him that Eva's known who he is from the beginning. Chuck tells Eva to leave, until Lily helps expose the truth. He runs back to his sweet amour to beg for forgiveness, but it's too late. With his one reason to stay good gone, the old Chuck Bass returns!