Sam, Clover, and Alex, along with the rest of Professor Plunkett's Fashion Design class, win a trip to Versailles where they will be guests at a fashion show showcasing the outfits of Marie Antoinette. When they get on the flight and their plane is nearly forced into the ocean as a result of Mandy's heavy luggage, they have no choice but to get into spy mode, regardless of being told by Jerry they wouldn't have to be doing any spying. Once they are in Versailles, things become hectic just as quickly. After the palace representative, Mr. Auguste, tells them to make themselves at home in their posh surroundings, Jerry breaks his promise and sends the girls to check out a break-in at the nearby Palais du Luxembourg. The spies find a clue - what appears to be a missing key - as they return to Versailles and find the place under assault by a mysterious attacker!