TWO-HOUR SERIES FINALE (8pm – 10pm)– GOSSIP GIRL IDENTITY REVEALED IN SERIES FINALE — The Series Finale begins with the stars and executive producers bidding farewell to the Upper East Side in a look back at the show’s many unforgettable moments. Then, in a fashionable farewell to remember, our favorite Upper East Siders join forces for one last soiree, and the shocking identity of Gossip Girl is finally revealed.  Blake Lively, Leighton Meester, Penn Badgley, Ed Westwick, Chace Crawford, Kaylee DeFer, Kelly Rutherford and Matthew Settle star.  Mark Piznarski directed the episode written by Stephanie Savage.

AND LET THERE BE THANKS — Serena (Blake Lively) and Dan (Penn Badgley) decide to throw their first Thanksgiving together, inviting only their closest friends, but everyone seems to have their own agenda for attending. Feeling defeated by his father (guest star Robert John Burke), Chuck (Ed Westwick) begins a downward spiral, leaving Blair (Leighton Meester) to find a solution to his problems. Meanwhile, Dan has written his latest exposé, but he must make a tough decision whether to publish it, knowing it could destroy a close friendship. Chace Crawford, Kelly Rutherford and Matthew Settle also star. Barry Watson and Sofia Black-D’Elia guest star. John Stephens directed the episode written by Jake Coburn.

“THE PRICE YOU PAY — Blair (Leighton Meester) gets ready for her mother’s (guest star Margaret Colin) imminent arrival, but is unprepared for the set of demands her mother puts upon her. Serena (Blake Lively) volunteers to help Dan (Penn Badgley) find a new place to live, but their time together brings up unexpected emotions. With Ivy’s (Kaylee DeFer) help, Chuck (Ed Westwick) discovers there is evidence incriminating his father in illegal activities and enlists the help of Nate (Chace Crawford) to retrieve it. Meanwhile, Rufus (Matthew Settle) and Ivy are excited about their art gallery opening until they find an empty RSVP list and must scramble to find another way to make the event a success. Kelly Rutherford also stars. Norman Buckley directed the episode written by Dan Steele.

DEAD ENDS — Chuck’s (Ed Westwick) continued investigation into his father’s dealings leads him to an unlikely event with Manhattan’s elite, where he hopes to find the one person who can tell him the truth about Bart (guest star Robert John Burke).  Serena (Blake Lively) and Steven (guest star Barry Watson) decide to reveal their romantic histories so they aren’t surprised by anything, but neither was prepared for what they uncovered.  With The Spectator in jeopardy after Dan (Penn Badgley) decided to publish elsewhere, Nate (Chace Crawford) must make a difficult decision to keep it in business. Meanwhile, Georgina (guest star Michelle Trachtenberg) pushes Dan to choose a worthy person to date to boost his image, but he finds himself drawn in a different direction. Leighton Meester, Kelly Rutherford, Matthew Settle and Kaylee DeFer also star. Sofia Black-D’Elia guest stars.  Andy Wolk directed the episode written by Matt Whitney.

“GOSSIP GIRL” — (9:00-10:00 p.m. ET)
“Dirty Rotten Scandals” (TV-14, D) (HDTV)

TESTING RELATIONSHIPS / ALEXA CHUNG GUEST STARS — Feeling the pressure to make her first Waldorf Designs fashion show a success, Blair (Leighton Meester) must rely on help from an unlikely source, but some unexpected scheming causes a scandal on the runway.  Serena (Blake Lively) discovers that befriending Steven’s (guest star Barry Watson) daughter Sage (guest star Sofia Black-D’Elia) is trickier than she thought, especially when she is forced to put her issues with Blair aside to make Sage happy.  Nate (Chace Crawford) publishes Dan’s (Penn Badgley) first serialized article causing a stir and producing a serious threat.  Meanwhile, Chuck (Ed Westwick) begins to look into the clue that Amira (guest star Andrea Gabriel) left behind, which may help uncover what Bart (guest star Robert John Burke) is hiding.  Kelly Rutherford and Matthew Settle also star. Bart Wenrich directed the episode written by Natalie Krinsky (#603).

THE SUMMER IS OVER AND SERENA HAS GONE MISSING / BARRY WATSON (“7th HEAVEN”) AND ANDREA GABRIEL (“LOST”) GUEST STAR — After a brief encounter abroad, Chuck (Ed Westwick) and Blair (Leighton Meester) make a promise to each other about their relationship, which leaves them once again apart. Dan (Penn Badgley), with some help from an unlikely ally, Georgina (guest star Michelle Trachtenberg), is writing a scathing tell-all book that can only mean trouble. As the sole head of The Spectator, Nate (Chace Crawford) is making his own decisions and is ready to go up against Gossip Girl. As word spreads that Serena (Blake Lively) is missing, the gang bands together to find her and are shocked by what they find. Robert John Burke and Sofia Black-D’Elia (“Skins”) guest star. Mark Piznarski directed the episode written by Stephanie Savage and Josh Schwartz.