Blair (Leighton Meester), who finally got the royal approval, is busy preparing for her wedding and Chuck (Ed Westwick) and Dan (Penn Badgley)'s love. Serena (Blake Lively) meets her cousin Charlie, whom she hasn't seen for many years, in Los Angeles and brings her back to Manhattan, but she doesn't know that she is an imposter and hides a big secret. Dan uses the stories of people around him to publish his novel "The Outsider", which has become the focus of the spotlight, but offends all his friends. Nate (Chace Crawford) starts working at "The NY Spectator" and meets Diana, who still has charm, and she seems to know the true identity of Chuck's mother. In the process of tracking, he finds that his father Bart is not dead... The Upper East Side is always entangled in secrets. How big a surprise will it bring this time? Everything is revealed by Gossip Girl.