MONDAY, OCTOBER 29

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

"Portrait of a Lady Alexander" (TV-14) (HDTV)

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. Matt Whitney directed the episode written by Andy Wolk (#604).