"That bitch got me remanded to rehab, banished from Bible camp and abandoned in Belarus ... all for her own enjoyment! If this is supposed to be her happiest day, then I can't wait to rain all over her parade." - Georgina.

If you were curious what prompts Georgina Sparks' return to Gossip Girl and why she might throw a wrench into Blair's big day, she runs down a whole list of reasons in a newly-released sneak peek from Monday's episode.

In a new clip montage, Georgina makes clear her intentions of a takedown, while the reality of getting married hits B hard. Fortunately, Serena is a good Maid of Honor and helps warm up those cold feet ... for now.

The third segment of the video below is one we've already seen, as Nate makes an interesting introduction and reflects upon his past relationships. Charlie's role in this episode is definitely a huge question mark / wild card.

See our Gossip Girl videos page for all the clips and promos from the 100th episode event so far. Then get your first glimpse at G's wrath in the latest sneak preview of the much-anticipated "G.G." below ...

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.