As the summer draws to a close in the Hamptons, Serena and Nate have everyone fooled into thinking they are a couple to cover up the fact that Nate has been hooking up with a married, older woman. Blair returns from abroad with a hot guy on her arm, making a very jealous Chuck question his decision to leave Blair stranded at the heliport. Dan has spent the summer assisting a famous author. While interning for Eleanor Waldorf's company, Jenny sneaks an invite to a much-coveted Hamptons' White Party at which Eric introduces her to socialite Tinsley Mortimer.

In the midst of Fashion Week, a furious Blair learns that her mother, Eleanor, at the suggestion of her protege Jenny, has given Serena and her new socialite friend, Poppy Lifton, front row seats to the Eleanor Waldorf show. Hurt once again by Serena's popularity and her mother's betrayal, Blair decides to sabotage the show. Meanwhile, Dan starts hanging out with Chuck, but a walk on the dark side always has its risks and Dan learns that the hard way. Lily learns a secret that her new husband, Bart, has been keeping from her.