Although scoring the highest mark in the final examination, cadet Chan Chi-chiu is sent to an outbound island because he has irritated inspector Lau Fook. He quickly gets promoted after he catches the gang leader in a fight. He also wins the friendship of Sister San, a big sister of a gang. Lau Fook is unable to manage a raping case committed by the British army in a village. His nephew, Lau Woo wants to frame Chi-chiu up but the case is resolved by Chi-chiu. Using the chance to make Lau Fook a hero, Chi-chiu wins the trust of Lau Fook. This provokes jealousy of his colleagues Luke Lui and Lam Kwong. Chi-chiu has a wife Ho Yuk-chu and a mistress Pak So-fan. He is also engaged in many affairs and this upsets So-fan. She tries to commit suicide and involves in extramarital affair to win back her man. When she fails, she sadly separates from Chi-chiu. Since Chi-chiu knows the techniques to flatter Lau Fook, he is appointed the successor of Lau Fook's position. Chi-chiu swears that he will try his best to help the poor and fight against the evils. Therefore when he knows that Lau Woo sells a young singer Kwok Chou-kuk to Sir Ha for money and forces her to death, he arrests Lau Woo to revenge for Chou-kuk. This further irritates Lau Woo's boss, Luke. Before Lau Fook dies, he begs Chi-chiu to leave his nephew alone. In the fifties, Chi-chiu has done a good job in settling many riots and is appointed the head of a new department, nicknamed "Three Flags". This means he is now the man who has absolute police power in hand.