2.05 "The Serena Also Rises"

As Gossip Girl narrates the so-called Fashion Week where the students of the Upper East Side gather for the annual fund raiser, Blair becomes angry with her mother when she gives Serena and her new socialite friend, Poppy Lifton, front row seats to the Eleanor Waldorf Fashion Show. Hurt and betrayed by both Serena and her mother, Blair decides to sabotage the show. Meanwhile, Dan, also humiliated and shunned by Serena (who has fully returned to her former bad-girl self), starts hanging out with Chuck and his life of parties. Dan quickly learns that living the life of the dark side has its risks. Also, Lily learns a secret that her new husband, Bart Bass, has been keeping from her.