Blair puts pressure on Georgina to making amends for her past bad behavior by helping her in an evil plan. The rivalry between Nate and Chuck over Blair reaches a boiling point. Lily makes a secret plan to help Rufus with Dan's college tuition.

In need of publicity for his new hotel, Chuck decides to move up his club’s opening and enlists Serena’s help to get the word out to her celebrity clients. Feeling left out of the planning, Blair attempts to win Chuck’s approval by secretly helping him with a problem concerning opening night. Dan is unnerved when he finally watches one of Olivia’s infamous sex scenes with co-star and real-life boyfriend at the time, Patrick Robinson. Jenny is forced to choose between her relationship with Eric and her new role as Queen Bee. Rufus gets Lily into the Halloween spirit.

Nate and Serena decide to explore the boundaries of their friendship. Blair suspects that Chuck is having problems forgetting about the woman he saw at his father’s grave. Jenny agrees to accompany Damien to a State Dinner but is unaware that he needs her help with a drug exchange. Vanessa and Dan attempt to move past the awkwardness of Dan’s confession of love. Rufus returns from a ski trip and tries his best to avoid Lily.

When things get tense between Rufus and Will, Serena chooses to stand behind her father, while at the Rufus is made to feel like an outsider in his own family. Meanwhile, Jenny deliberately shares information with Will that may ultimately destroy Lily and Rufus' marriage. After many failed attempts, Chuck makes one last grand gesture to reconcile with Blair, hoping she will finally accept the fact that they are destined to be together.

Living out a real-life fairytale in Paris, Blair is pursued by a handsome young man, Louis, who she suspects is a member of Monaco's royal family. A very concerned Lily asks Serena to help her find Chuck, who hasn't been heard from or seen in months. Meanwhile, Chuck Bass is as we've never seen him before, adjusting to a fresh start in Paris with a mysterious new woman, Eva, at his side. Juliet offers to help Nate win Serena back, suggesting that reigniting Dan and Vanessa's romance may just be the trick to remove Dan from the Dan-Serena-Nate love triangle.

Chuck hosts a "Saints and Sinners" masquerade party at the Empire Hotel. At the party, Dan and Nate don't know what to make of Serena's strange behavior and mixed messages. Blair sets her sights on becoming the new face of Anne Archibald's foundation for girls, but Anne is concerned that Blair's friendship with Chuck Bass may be problematic.

Nate reconnects unexpectedly with Diana, who offers him an exciting opportunity. Serena forces Charlie to decide which world she wants to embrace. Dan seeks out Chuck’s help to stop the publication of his book, but discovers it is Chuck who needs the help. Blair’s future sister-in-law, Beatrice, arrives from Monaco, but her motives with Blair may be more than just to get acquainted.

Blair's flashbacks reveal the fallout of her and Chuck's car accident, which Nate realizes may have been caused by foul play. Meanwhile, Lily gets a private eye to locate Charlie; and Vera Wang makes an appearance at Blair's bridal-dress fitting.

After Eleanor gives Blair an ultimatum, Blair is even more determined to remedy Waldorf Designs’ problems by making a splash with a dress at the upcoming Cotillion, but a shocking revelation at the ball affects everyone. Serena becomes worried about Steven’s attitude toward her, but after some investigating she discovers the surprising reason why. Chuck finds an unlikely ally as he tries to drive a wedge between Bart and Lily’s relationship to help expose his father’s secret. Meanwhile, Dan publishes another article, but the effect is just the opposite of what he was hoping for.

After a run-in with an increasingly paranoid Bart, Blair grows alarmingly concerned for Chuck’s safety. However, feeling confident that his father will never hurt him, Chuck makes a deal that could change his life. Wanting to make things better for Chuck, Blair devises a plan with the help of Serena, Georgina and Sage to try and get what they need out of Bart. Meanwhile, Nate's financial dilemma finally lands him in a place that he never thought he would be.