Meanwhile, the boys' aunt and uncle, Esther and Max Hartlieb ( Carole Boyd and Bob Goody), have traveled to Venice in order to find their nephews and entreated the help of Victor Getz ( Jim Carter). Barbarossa tells Riccio and Prosper there is a client who needs something stolen and is willing to pay big money for it. Bo brags that Prosper "is great at selling things" and Prosper ends up getting Barbarossa to quintuple his asking price. Unfortunately, Barbarossa - the sleazy antique dealer the children have to sell their stolen goods to - always cheats the children.
They steal from stores and Venice's wealthy tourists, but the majority of their money comes from Scipio, who goes on mysterious raids and always brings back treasures. The Stella is also home to three orphaned children Scipio has rescued: Hornet ( Alice Connor), Riccio ( George MacKay) and Mosca (Lathaniel Dyer).
The Thief Lord, a mask-wearing teenager whose name is Scipio, invites the boys to come with him to his hideout, an abandoned movie theatre called the Stella. The boys are nearly caught and lose the rest of their food, but are rescued by the mysterious Thief Lord ( Rollo Weeks). Bo becomes ill and Prosper is forced to resort to stealing cough medicine from a pharmacy. Once in Venice, the boys live on the streets, and the money Prosper brought quickly runs out. However, before they can separate the two boys Prosper takes Bo to Venice, the magical city about which their mother often told stories. She plans to send twelve-year-old Prosper (Aaron Johnson) away to boarding school.
When Prosper and Boniface's parents die, their aunt Esther attempts to adopt the younger brother, an adorable five-year-old who eventually turns six as the movie progresses, named Bo ( Jasper Harris).
The first edition of this novel by international bestselling children's author, Cornelia Funke.