Horrible Harry thinks he s the world s second-best detective second only to Sherlock Holmes, of course. But the rest of the kids in Room 3B aren t so sure. So he s determined to prove himself by solving the latest mystery at South School how to win the new cafeteria contest. He knows the cafeteria lady is using a special mathematical code, but can he crack the code before his classmate Mary tattles on him again? Or will the case go cold right before Harry s eyes?
