Summer in the Hamptons!!! Serena and Nate fake their relationship as covers for Nate's affair with a married woman named Catherine Mason and Serena's mourning for her relationship with Dan. Blair returns with a new boyfriend James making Chuck jealous. Dan spent the summer assisting but leaves to see how things stand with Serena. Jenny interns for Eleanor's company and manages to sneak in to an exclusive white party with help from Eric who then introduces her socialite Tinsley Mortimer.