Leung Foon is a happy-go-lucky man with a girlfriend named Pizza and he is a police detective in the Happy Valley, Hong Kong Police Station tasked of being a small-time undercover with his superior nicknamed "Thousand Faced Man" but after their undercover case of protecting a millionaire's daughter nearly failed, Leung was tired of taking undercover work and even protested to quit the police force if he's not given a big-time case. Eventually "Thousand Faced" gave Leung the biggest task of bringing a big-time swindler named Ferrari to justice with a promotion being the reward despite Leung failing his "preparedness test".