As the summer draws to a close in the Hamptons, Serena (Blake Lively) and Nate (Chace Crawford) 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 (guest star Amick) and Serena has been secretly mourning her break-up with Dan (Penn Badgley). Blair (Leighton Meester) returns from abroad with a hot guy on her arm (guest star Patrick Heusinger), making a very jealous Chuck (Ed Westwick) question his decision to leave Blair stranded at the heliport. Dan has spent the summer assisting a famous author (guest star McInerney), but decides to head to the Hamptons to see how things stand with Serena after a summer spent apart. While interning for Eleanor Waldorf's company, Jenny (Taylor Momsen) sneaks an invite to a much-coveted Hamptons' White Party at which Eric (Connor Paolo) introduces her to socialite Tinsley Mortimer.