Summary

One in this series of animated children's programs from France and Italy about the adventures of Orson and Olivia, two 19th-century London street urchins who survive by their wits and live with their dog, Falstaff, at Rat's Castle. In this episode, Olivia is captured by a cruel constable and sold to the evil headmistress of a city orphanage. While at the dreary orphans' home, Olivia meets Henriette Desmond, a rich girl whose ill mother placed her in the orphanage just before she died. The youngster claims that the headmistress has stolen the jewels that Henriette's late mother bequeathed to her. She also tells Olivia that her brother, who is an ensign, is soon returning to London on a ship. When Olivia manages to escape and Henriette follows her, Orson follows the two to the docks, where they discover that the heiress's brother has sailed away for four more months. Henriette is distraught about being alone, but Olivia is too jealous to allow the aristocratic youngster to live with her and Orson, especially after she proves to be a poor rat catcher. The two girls gain each other's respect, however, as they concoct a plan to recover Henriette's jewels while exposing the constable's dastardly behavior.