Nancy's all dressed-up, with a place to go! But so is Nancy's jealous rival, Deirdre Shannon, in the exact same dress, going to the exact same place, her big party! But the really bad stuff starts when Nancy is suddenly kidnapped, and it wasn't by the fashion police. Can Nancy's friends, Bess, George, and Ned solve the mystery of the missing Girl Detective, or does the Teen Sleuth face a fate far worse than a mere wardrobe malfunction?