Blair is feeling heartbroken and guilty by the current state of her relationship with Nate and her recent indiscretion. But she manages to put on a happy face for her 17th birthday party and attempts to hide her feelings from her friends. Hoping that Serena and Vanessa can bond, Dan takes Vanessa to Blair's birthday party. Jenny brings her mother home as a surprise, but Rufus isn't ready to forgive and forget. Finally, Nate's parents ask him to make a huge sacrifice to save his father's business.