After Eleanor gives Blair an ultimatum, Blair is even more determined to remedy Waldorf Designsโ problems by making a splash with a dress at the upcoming Cotillion, but a shocking revelation at the ball affects everyone. Serena becomes worried about Stevenโs attitude toward her, but after some investigating she discovers the surprising reason why. Chuck finds an unlikely ally as he tries to drive a wedge between Bart and Lilyโs relationship to help expose his fatherโs secret. Meanwhile, Dan publishes another article, but the effect is just the opposite of what he was hoping for.