MONDAY, OCTOBER 18

"GOSSIP GIRL" - (9:00-10:00 p.m. ET)

"Belles de Jour" (TV-14, D) (HDTV)

SEASON FOUR KICKS OFF IN THE CITY OF LIGHTS! OMP! - Blair (Leighton Meester) has spent a fabulous summer in Paris without realizing her former love, Chuck Bass (Ed Westwick), has been shot. As much as Blair tries to distract herself from the pain Chuck caused her, his mysterious appearance in Paris with a beautiful new woman (guest star Cl�mence Po�sy) will force both of them to face what happened. Meanwhile, a newly single Serena (Blake Lively) has been enjoying a Parisian summer of love with boys, Blair and Balenciaga as she tries to avoid the inevitable decision about which of her two long-time beaus, Dan or Nate (Penn Badgley and Chace Crawford), she should return to. Back on the Upper East Side, Nate meets an intriguing girl, Juliet (guest star Katie Cassidy, "Melrose Place"), who helps him realize that his summer of sexual conquests with the help of Chuck's little black book was his way of avoiding his unresolved feelings for Serena. Meanwhile, Dan's (Penn Badgley) baby mama drama continues with Georgina (guest star Michelle Trachtenberg). Finally, the van der Woodsen apartment is buzzing with activity as the "Fashion's Night Out" event is planned. Jessica Szohr, Kelly Rutherford and Matthew Settle also star. Mark Piznarski directed the episode written by executive producers Joshua Safran and Stephanie Savage (#401).