North Carolina teens TD and his younger sister, Virginie, accompany their dying mother on a final trip to her birthplace, Paris. While on a walk,TD sees two men trying to shove two girls into a van. He rescues them. The girls, Caroline (17) and Jackie (13) are the youngest if the enormously wealthy Arroux family. TD's mother dies after they return to the States. He and Virginie accept the Arroux's invitation to come live with them in France.
The four teens, watched over by bodyguards, enjoy a peaceful trip on one of the Arroux's luxury barges, when the barge is attacked. They and their pudgy fellow traveler, Humpy, escape just before the barge explodes and find themselves on the estate of the widow, Lillian Deveraux. Humpy and Lillian grow fond of each other as do Caroline and TD.
Who is trying to kidnap the girls? Is it an inside job? What will they try next? The Arroux hatch a plan to trap the kidnappers into revealing themselves by seeming to make it easy for the deed to get done on a trip to Brittany. Body doubles replace the teens who are then spirited away to the Arroux house in Paris. The plan fails. The teens are captured and held in an abandoned wine cave in Burgundy.
The tension becomes almost unbearable, but once again the bad guys' plans fail as they fall out among themselves and the teens outsmart them. They capture the ringleader and end the chance of any further kidnapping attempts.
Caroline transfers from the Sorbonne to be with TD at the University of North Carolina.