The story takes place a few years from the first series.
Chu So Ngo has been promoted to sergeant rank in the police but she encounters professional setbacks due to her new responsibilities. She depends on fellow cop Chan Siu Sang who is now her boyfriend for support and a secure future, and hopes for him to get promoted soon. They plan to get married. The added pressure of waiting for a promotion and So Ngo depending on him gets to Siu Sang, and he finds some breathing room with Sum Yeo, his beautiful next-door neighbor whom he sees as a platonic friend. When So Ngo finds out that she cannot have any more children, she rethinks whether she and Siu Sang should really get married. With all the added pressure in their relationship, both decide to break up. Siu Sang finds relief in Sum Yeo, whom he dates briefly and soon marries. So Ngo starts a relationship with taxi driver Yeung Kwong Chiu, who thinks she looks like his dead wife. Sam Yuen and Ching Fung are also experiencing difficulties in their new marriage when San Yuan is transferred to the Special Police Unit and concentrates more on her career than family, leaving Ching Fung alone at home. Feeling neglected by his wife, Fung develops a drinking problem, which leads to a one-night stand with a stranger. With their marriage in jeopardy, Sam Yuen further buries herself in her in her career, putting all her concentration into her current case regarding a serial psycho sex offender taxi driver wanted by the cops. When Sam Yuen becomes the psycho sex offender's next victim, Ching Fung is there for her, to help her heal. (Source: Wikipedia)