Nate and Sage hunt for clues about Gossip Girl's identity, figuring that she'd have to be around their age, but it's Dan's final chapter that provides the missing link. The Spectator publishes Dan's piece, and the reveal scene is pretty epic — we see tons of past characters reacting to the news, along with a special appearance by Rachel Bilson and "Gossip Girl" herself, Kristen Bell. And then we find out . . .