Madeline's Detective School. To raise money to buy Miss Clavel a birthday present, Madeline starts a detective school. Meanwhile, Miss Clavel is receiving mysterious gifts of great value - jewels, a painting, etc. Inspector Moreau discovers they are stolen by the infamous cat burglar Le Chat and arrives to question Miss Clavel. Madeline and her students use their detective skills to apprehend Le Chat, who was once a reform student of Miss Clavel's and has been working at the Old House as a painter and gardener. The stolen items are returned, Le Chat is locked up and the girls discover that they do not need a lot of money to get Miss Clavel a present that she will always cherish.