The Upper East Siders are working together to find Serena who has gone off the grid. Her friends fear for the worst, but even they can't imagine where to find her. Blair has offered Chuck her heart, but is her love enough to help win back his empire? Dan has written a new book that promises to make more trouble and this time he has no desire to remain anonymous. Nate is determined to finally reveal the true identity of Gossip Girl, thereby making...