When Gossip Girl goes after Blair as she�s never done before, Serena admits she may have unintentionally played an important role in Blair�s latest nightmare. Meanwhile, Nate invites Lola to move in with him, and Lily must make a big decision about the future of her marriage. Finally, by episode�s end, Blair will make a choice between the two men in her life�will it be Chuck or will it be Dan?