MOK KWAI-LAN has been looking for her sworn brother YAU SUM-SHUI, who is a waiter of Fook Yue Kui restaurant, everywhere. She finds him gambling in an illegal boxing gymnasium at last. SHUI has bet on dark horse LUI CHING-LUNG, nicknamed the IRON MONEY. He is on his way to collect his prize money, but somebody else picks up his stub. He has a fight with that person.