Ten-year-old Penny Pepper is a clever brainiac who dreams of becoming a super detective and solving a real crime. She did not expect that the chance to prove herself would arise during the party of the boastful Flora. Flora's dog suddenly and without a trace disappears, and for some reason all the guests suspect Penny. Don't panic ! Everything is under control. Together with her best friends, the girl is willing to do anything to expose the insidious thief. Even to save her old enemy..