Returns: Monday, April 21, at 8 pm/ET Number of new episodes: 5 Where we left off: As ex-virgin queen bee Blair faced public scorn for her limo liaison with Chuck, Jenny stood to inherit her throne, and Serena kept Dan in the dark about her past. What's next: The action moves to Mondays for a clash of the teen titans. "Blair is on the warpath," tattles exec producer Stephanie Savage. "[You] wouldn't want to be Jenny Humphrey right now." We may also learn what really sent Serena running off to boarding school. (Enter new cast member Michelle Trachtenberg.) Wedding wow: Savage promises the adults will get their drama on, too. "Expect the most extravagant wedding the Upper East Side has ever seen." You know you love it. Watch full episodes | Photos | More Returning Favorites coverage