Geronimo's adventurous sister Thea narrates this fabulous adventure that's packed with action, mystery, and friendship! In this exciting adventure, the Thea Sisters are off to Paris to visit Colette's fashion-designer friend Julie. But when Julie's designs are suddenly stolen, the girls must search the city of Paris to catch the thief and save the fashion show. Readers will love following the clues to help the Thea Sisters solve the mystery!