A blundering Hong Kong police inspector, Ma Yu Long, goes under cover to investigate a high-class businessman, Teng Kuo Chiao, who was bribing city planning officer Ma Yu Yu to build roads to suit his needs and is suspected to be liable in Yu's death. In the meantime, Long courts Yu's high school sweetheart, Julia, who wants the inspector to cheat Chiao out of some money as part of the revenge deal.