Uncles Luk runs into heavy debts and wants to sell his daughter to a brothel. Driven by his sense of justice, Yung Yuet San offers help and save Hau Yee, Luk's daughter from becoming a prostitute. San even gets a job for her in Ngai Pang's house. Ip Yuen Sham is impressed by his act. Ngai Pang is the ring-leader of an underworld gang. Both San and Kong Chun Shing are working for him. Shing is once ridiculed by Lui Lung who is the enemy of Pang and he feels very angry. Shing is already engaged to Fong Wing Chuen, the niece of Sister Lau who worries about his unrestrained character. She keeps asking him to reform but he pay no heed to her words. Uncle Cheung's son is seriously sick and he has difficulty in paying the medical charges. Owing to Fang's help, Pang promises to lend him the money. However, Shing refuses to give Cheung the money and he even scolds Cheung fiercely.… ...

Fang is killed when the gangsters try to kidnap Pang. It greatly grieves Pang. San and Ko Han try to locate Pang. San is suspicious of Cheung and he follows him. Yet he is discovered and is wounded in the end. Eventually, San and Han find out Pang's whereabouts and successfully save him. Pang kills the murderer of Fang as a revenge. On the other hand, Shing thinks that Pang is kidnapped by Lung. So he sends his followers to raid Lung's dens. This antagonises Lung. Knowing that Shing has done wrong to Lung, Pang is forced to compensate for his loses. To vent his anger, Shing kills Cheung secretly. He tries to hide this from Pang who gradually loses trust in him. San now becomes Pang's right hand man.

Poon Yuet Wah is angry to learn that San is working in the underworld. But San successfully pacifies her with his glib tongue. Pang asks San and Shing their opinion concerning his collaboration with Mo Kin. San and Shing hold different opinions but Pang takes sides with San making Shing very unhappy. Chuen comes to live with Lau in Hong Kong. San goes to meet her at the 4tation. Shing is trying to avoid her since he fears that she is no good-looking at all. Chuen feels very unhappy about that while San leaves a favourable impression upon her. San and Shan are preparing to get married. Chuen offers them a hand. By accident, Shing meets her and is attracted by her. Pang also meets a very beautiful girl, Chou Ying and starts to court her.

Chou Tat Fu happens to find the lost wallet of Shing and gambles away the money. He is later discovered and is beaten. Ying comes in time to save him from the hands of Pang. By mistake, Ying hurts Han but Pang lets them go. Pang starts to date Ying and helps to settle Chou Moons debts. Ying feels indebted to his kindness and promises to marry Pang. After much negotiation, Kin and Pang enter into an agreement for collaboration. Accidentally, Wah finds Kin and San having a business meeting. She is greatly shocked to see Kin.

In fact, Wah recognizes Kin to be the murderer of her parents who at that time wanted to leave the gang. She is the witness and she tells this to San. After investigating, San knows that Kin is really the murderer but he does not dare to kill him because that will bring trouble to Pang. Knowing this, Pang thanks San for -- being so considerate and sends him a flat as his wedding present. Shing overhears their conversation and grows jealous of San. Later, San determines to have his revenge and withdraws from Pang's gang. Being close friends, Han decides to follow San who is greatly impressed. Shing betrays San and inform Kin of San's plan. Kin sends his followers to kill San. However, San escapes from the danger but Shan is shot dead.