In this sneak peek from "New York, I Love You XOXO," Monday's Gossip Girl series finale, Nate and Sage are looking over the evidence, considering the suspects and closing in on the mother of all mysteries.

Just who is Gossip Girl exactly? Do they know?

Apparently Jenny Humphrey, who was Sage's idol in seventh grade, is at least being talked about, but the conversation then turns to situations where Gossip Girl went easy on someone. That could be a clue.

She shut down after Chuck and Blair's accident, led Dan and Blair to Juliet after Serena was drugged, supposedly spared S before graduation. Who knows. Maybe she was a guardian angel of sorts?

With the last episode days away, Gossip Girl finale spoilers have ramped up speculation about who the title character is, who ends up together, and what the polarizing twist in the last 15 minutes could be.

Share your comments, and votes, below!

Who is Gossip Girl?

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