That's all she—or rather he—wrote. The last episode of Gossip Girl aired Monday night, and fans were finally treated to the secret identify of the Upper East Side troublemaker. It turns out it was Dan Humphrey who wrote all of those juicy missives all along, as a way to fit into a world he wasn't born into. Weird, because actress Kristen Bell actually did the voiceover work for the character. The finale saw not one but two weddings: Blair and Chuck tied the not, and so did Serena and Dan. As Dan said at the show’s end, "Gossip Girl is dead."