Chuck Bass (Ed Westwick) looks for a missing Blair Waldorf (Leighton Meester) who has been held hostage by an unstable Russell Thorpe (Michael Boatman).
An erratic Charlie Rhodes (Kaylee DeFer) escapes the humiliation of being rejected by Dan Humphrey (Penn Badgley).
Serena van der Woodsen (Blake Lively) and Vanessa Abrams (Jessica Szohr) reluctantly join forces after discovering the secret behind Charlie's behavior.
Jessica Szohr makes her final appearance as Vanessa Abrams; her exit was noted as her highlight of season 4, with many critics praising Szhor's acting in her phone conversation with Dan.
While accompanying Chuck to their apartment to look for Blair, Nate confesses that he told Raina (Tika Sumpter) everything behind her mother's death.
With the police arriving, Chuck offers Blair a limo ride, and a homesick Raina breaks up with Nate, intending to return to Chicago.
Chuck proposes avoiding the Constance party by going to a bar mitzvah in a similar fashion to Death Takes a Holiday, which Blair accepts.
Dan decides to spend summer in The Hamptons with Eric (Connor Paolo) and tells Rufus (Matthew Settle) that he has moved on from writing.
In Miami, Carol (Sheila Kelley) pays Charlie, who is actually a con artist named Ivy that was hired to gain access to her daughter's trust fund.
A later scene shows a positive pregnancy test in a trash can at Blair's bathroom being thrown out by Dorota (Zuzanna Szadkowski).
"[3]Following her role in Green Lantern, news surfaced of Blake Lively leaving the show to further her acting career in Hollywood.
IOL notes "Despite all talk of career trajectories and fanbase, Blake insists her choices are made through far simpler criteria and when asked about playing in a comic-book film says: 'It’s not really a suitable question because the decisions I make on parts come from a more emotional place.
Hugo Becker remained ambiguous on whether he would be joining the series as a recurring or regular cast member during an interview with Zap2it, stating "the answer is in the finale."
[16] The Airborne Toxic Event made a special appearance as the band for the Constance Billard Alumni party, playing the song "Changing" from their sophomore album, All at Once.
"The Last Episode of the Fourth Season of the Greatest Show of Our Time felt in many ways like it might have been written to end the series, what with the many This Is Your Life moments (such as the return of Georgina Sparks and Blair's old minions Izzy and Kati), the wry references to episodes past, the wrapping up of story lines (including the revelation that Dan has been secretly novelizing his observations of the Upper East Side for the entire time we've thought we've "known" him), and the meaningful departure of its most marketable star to none other than Hollywood."
"[21] Television Without Pity and Steve Marsi of TV Fanatic praised the return of Georgina, stating "Michelle had some of the show's funniest dialogue in a long time.
I had my doubts and reservations, largely concerning Blair and Chuck, but I am surprised and pleased to report that I found the end of "Gossip Girl" Season 4 both exciting and satisfying."
Berman also questioned Vanessa's motive behind publishing Dan's novel "[...]it's impossible to know whether she's trying to do her old friend one last favor or profit from stirring up more drama in his life.