Kan Yiu-yeung, Ku Ka-keung, Kiu Po-po and Kiu Tai-nam were once CTRU’s Formidable Quartet. An incorrect decision in an operation caused the breakup of their friendship. And the quartet went their separate ways. Fast-forward to the present and an indiscriminate homicide again brings the quartet together. But there are still certain unresolved issues between themselves. POTT is Counter Terrorism Intelligence Cadre’s other elite task force. Team leader Fong Kwok-hei admires Po-po and asks her to become her subordinate. Team member To Siu-jie fancies her partner Yiu-yeung and finds out Po-po is Yiu-yeung’s ex-lover, so she “starts a war”. Successive explosions happen in the city. While investigating, Po-po asks prisoner-cum-hard criminal Dr. Hong’s for help, and the process is surprisingly easy. Actually, Dr. Hong has some trick up his sleeve.
Yeung Yut Ching, an elite in the bodyguard world, is good at risk management and is the winning team in life. However, his unhappy childhood made him refuse marriage, and fate made him meet Yau Tze Ching, a clever woman who keeps breaking the rules of his life.
In the 1930s, Bo Ching-wan and his family have come to crime infested Tong Yan Street in Bangkok. His father Bo Tin-ha tragically dies after he has teamed up with Lin Chun-shan to rebel against Lo Heung-tung. Ching-wan’s younger brother and sister have also gone missing. His mother Ting Sai-fung has become emotionally unstable. Twenty-five years later, Ching-wan sets foot in Tong Yan Street again and encounters a swindler called Chin Chin-chin. Chun-shan’s son Lin Gik turns out to be a corrupt cop. His colluding partners Pang Kin and Kam Lung are bosses of the two most notorious gangs. Pang Kin’s only son returns to Bangkok with his fiancée Ching On-na. However, he is assassinated, causing the two gangs to clash with each other. Ching-wan establishes Overseas Chinese Society of Bangkok. Ching-wan and his partners encourage good deeds and punish the baddies. The Society is in disarray as it repeatedly faces up to difficulties. There is still a long way to go before the chums find peace.