Sara Goodman

After a run-in with an increasingly paranoid Bart, Blair grows alarmingly concerned for Chuck's safety. However, feeling confident that his father will never hurt him, Chuck makes a deal that could change his life. Also available on Xfinity, CW, iTunes, Amazon Instant Video and VUDU

After Blair's mother, Eleanor (recurring guest star MARGARET COLIN), gives Blair an ultimatum, Blair is even more determined to remedy Waldorf Designs' problems by making a splash with a dress at the upcoming Cotillion - but a shocking revelation at the ballaffects everyone. Serena becomes worried about Steven's (recurring guest star BARRY WATSON) attitude toward her, but after some investigating she discovers the surprising reason why. Chuck finds an unlikely ally as he tries to drive a wedge between Bart (recurring guest star ROBERT JOHN BURKE) and Lily's relationship to help expose his father's secret. Meanwhile, Dan publishes another article, but the effect is just the opposite of what he was hoping for. Also available on Amazon Instant Video and VUDU

When Gossip Girl goes after Blair, Serena admits she may have played a role in Blair's latest nightmare. Plus, will Blair choose Chuck or Dan? Also available on iTunes, Amazon Instant Video and VUDU

Through a series of emotional flashbacks, Blair reveals to Serena what really happened in the aftermath of her tragic car accident with Chuck. Meanwhile, Nate discovers information about the accident that suggests possible foul play. Lily is worried by Charlie's long absence and decides to hire a private detective to track her down. VERA WANG makes a cameo as herself at Blair's dress fitting. Also available on Netflix, Amazon Instant Video and VUDU

Nate reconnects unexpectedly with Diana, who offers him an exciting opportunity. Blair's future sister-in-law, Beatrice, arrives from Monaco. Also available on iTunes, Amazon Instant Video and VUDU

En route to "happily ever after," Blair finds herself torn between the men in her life. Jack Bass returns to the Upper East Side. Also available on iTunes, Amazon Instant Video and VUDU

At Eric's 18th-birthday celebration, there is plenty of drama to go around. Serena is forced to choose between her family and Ben. Also available on iTunes, Amazon Instant Video and VUDU

Chuck throws a "Saints and Sinners" masquerade party. Blair sets her sights on becoming the new face of Anne Archibald's foundation for girls. Also available on iTunes, Amazon Instant Video and VUDU

When things get tense between Rufus and Will (recurring guest star WILLIAM "BILLY" BALDWIN), Serena chooses to stand behind her father, while Rufus is made to feel like an outsider within his own family. Meanwhile, Jenny deliberately shares information with Will that may ultimately destroy Lily and Rufus' marriage. And, after many failed attempts, Chuck makes one last grand gesture to reconcile with Blair, hoping she will finally accept the fact that they are destined to be together. Also available on Netflix, Amazon Instant Video and VUDU

Nate and Serena explore the boundaries of their friendship. Blair suspects that Chuck is having problems forgetting about the woman (recurring guest star LAURA HARRING - The Shield, Mulholland Drive, Sunset Beach) he saw at his father's grave. Jenny agrees to help Damien (recurring guest star KEVIN ZEGERS) overcome a challenge he faces. Vanessa and Dan attempt to move past the awkwardness of Dan's confession of love. Rufus returns from a ski trip and tries his best to avoid Lily. Also available on Netflix, Amazon Instant Video and VUDU