The episode begins with Chuck and Blair rushing out of the building from the roof of which Bart has just fallen. The cops arrive at the scene soon after. Bart’s body is covered by the cops and taken away. Blair gives Georgina a call. Dan has texted Daphne his editor that he will send her the last chapter, but is waiting for someone to get back to him. Serena on her way to LA finds the envelope Dan slipped into her luggage. In the envelope is the alternate piece, he had written about Serena. Serena on seeing the piece has second thoughts about leaving. Sage is helping Nate find out the true identity of Gossip Girl. Nate gets a text from Ivy asking him to turn on the TV.
On the news its being mentioned how a man has been found dead, outside the venue where Bart was being honored. It’s also mentioned that, the name of the deceased is being withheld for the moment. Lily gets a call and is shocked at what she is told. Ivy tells William it’s safe for him to come to the city, hinting that Bart isn’t around anymore. It’s then officially announced on the news that “the deceased is Bart Bass himself”. Blair and Chuck sneak out from near the venue in the boot of his limo. On the news it’s also mentioned that “Chuck Bass is a person of interest in this case”. It’s then clarified by the reporter that, being a person of interest doesn’t mean Chuck is a suspect, but the police feel Chuck might have some information about this case.
A cop questions Nate and he says when he got to the party, Chuck was already gone. The cops also question Blair’s family members about her whereabouts. Chuck and Blair are at some undisclosed location. Jack arrives at their room and tells them that Bart is dead. He also says that he is there to help. Dan sees that Serena is back. She says she spent the entire night reading and rereading what he wrote. Dan says whatever he has written is true. Serena says she is confused and doesn’t know what to think. She asks Dan which one is the real him, the one who wrote the chapter in Vanity Fair or the one who wrote the piece she is holding. Blair and Chuck tell Jack what exactly happened.
Jack suggests Chuck and Blair get married, so Blair can’t be forced to testify against Chuck. Blair is down with the idea but Chuck doesn’t feel it’s the right way. Blair talks him into it eventually. Chuck gets down on one knee and proposes to her. Blair accepts with tears in her eyes. Lily meets William and he expresses his deepest condolences at Bart’s passing. Lilly says she would be grateful for William to be by her side. William is more than happy to be by her side. He sees an incoming call from Ivy, but doesn’t receive it. Dan explains everything to Serena from the beginning. He tells her how he fell in love with her the first time he laid his eyes on her at a party.
Serena is impressed that Dan remembers such intricate details of their first meeting and it seems to break the ice, as they hold hands. Nate finds out the Spectator can be all his, now that Bart is dead. All he needs to do is pay off the loan. Blair and Chuck are at a courthouse. Jack enters and hands them their backdated marriage license, so that no one suspects the two got married for any reason other than their love for each other. Blair suggests that they now get officially married, but Chuck feels it’s not fair to Blair. He basically feels it’s not Blair’s dream wedding and also she doesn’t have the people she loves around her.
Blair insists she doesn’t need anyone, but Chuck hears none of it and drags her out of the courthouse. Jack picks Georgina up while she is walking down a street, as he needs her help. Ivy arrives at Lily’s apartment building and sees Lily and William together. She tells Lily that William and she are together, but William feigns ignorance and says he doesn’t know what Ivy is talking about. Ivy is shocked at William feigning ignorance but, tells Lily that William is in love with her and they have been working together for months. Lily doesn’t believe a word of what Ivy is saying and William on his part denies everything.
Lily leaves to get the doorman and William thanks Ivy for helping him get back Lily, the love of his life and the mother of his children. Ivy is livid, but William reminds her that she can do him no damage. She is dragged out of the building by the doorman. Jack and Georgina arrive at the scene just then. “What do you two want?” Lily asks the two. “You” they reply in unison. Georgina then meets Dan and Serena and asks them to come with her. Gossip Girl in the meantime reveals that Chuck is on his way to hand himself over to the cops. Jack arrives at Nate’s apartment and asks Sage and Nate to come along with him.
All the people who Jack and Georgina have gathered are brought to a museum. Chuck and Blair are there and they inform everyone they are getting married. Chuck says he wanted friends and family to be around, when they got married. The whole gang mobilizes to prepare for the wedding. Two girls, who know Blair and Chuck, spy on this meeting. “This is the biggest Gossip Girl story ever” says one of the girls. Dan later overhears Blair telling Serena how she will never end up with someone like Dan who is a “powerless striver”. Dan is hurt by this comment, although Serena feels Dan deserves another chance.
Dan runs into Georgina and says he needs to take care of something and leaves. Dan later hands Nate his final chapter which is about Gossip Girl. Nate is overjoyed at Dan giving him the final chapter to publish in the Spectator. “Thanks man. This could change my life” Nate hugs Dan and says. Nate overhears the two girls who were spying earlier, calling the cops regarding Chuck’s whereabouts. Chuck and Blair are pronounced man and wife, seconds before the cops arrive at the scene. Chuck and Blair are then hauled away by the cops. It is revealed through Dan’s final chapter that he is Gossip Girl.
The whole town is shocked after they read about it in the Spectator. Dan explains that he became Gossip Girl because he wanted to fit in with the Upper East Siders, something which he could never do. So he decided to give the world an outsider’s view of the Upper East Siders. He mentions that Serena was his muse. He explains how the whole concept of Gossip Girl evolved over the years and each time Serena was the catalyst. Dan tells Rufus that Jenny knew for years that he is Gossip Girl. Chuck and Blair are released by the cops, as there isn’t evidence to hold them or link them to Bart’s death.
Everybody comes to terms with the fact that Dan is Gossip Girl and they are cool about it. Dan feels now that everybody’s life is sorted out, it’s time for Gossip Girl to die. Flash forward to 5 years later and Nate seems to have made the Spectator a success. Nate might even be a possible mayoral candidate. Chuck and Blair have a son named Henry. Serena and Dan are about to get married and the whole gang is present. There is also the hint of the emergence, of a new Gossip Girl. The episode ends at this point.