MONDAY, SEPTEMBER 20

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

"Double Identity" (TV-14) (HDTV)

GOSSIP GIRL GOES PARIS! - Living out a real-life fairytale in Paris, Blair (Leighton Meester) is pursued by a handsome young man, Louis (guest star Hugo Becker), who she suspects is a member of Monaco's royal family. A very concerned Lily (Kelly Rutherford) asks Serena (Blake Lively) to help her find Chuck (Ed Westwick), 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 (guest star Cl�mence Po�sy), at his side. Juliet (guest star Katie Cassidy) offers to help Nate (Chace Crawford) win Serena (Blake Lively) back, suggesting that reigniting Dan (Penn Badgley) and Vanessa's (Jessica Szohr) romance may just be the trick to remove Dan from the Dan-Serena-Nate love triangle. Matthew Settle also stars. Mark Piznarski directed the episode written by executive producers Joshua Safran and Stephanie Savage (#401).