Serena throws Jenny a sixteenth birthday party, but things spin out of control when Poppy Lifton turns the party into the social event of the season. Vanessa agrees to help Chuck in a plan concerning Blair and Nate. Meanwhile, Rufus searches for a way to cover Dan's tuition when he learns he will not receive financial aid to go to Yale.

Charlie is finally starting to feel less like a fish-out-of-water with Serena and her friends, but complications present themselves when Charlie is invited to attend the Constance Billard alumni fundraiser. On the road to "happily ever after" Blair finds herself torn between the men in her life. Jack Bass return to the Upper East Side sets off a chain of events that could end up destroying Chuck and those closest to him.