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.

During the a chaotic period of Imperial China, before the unification of the country, there exist two opposing regimes: the Song and Jin.

Surfer Ko Tsz Kit, who runs a B&B in Taiwan, is ambushed by assassins. Though he is saved by the agile backpacker Yuen Ching Yan, his adoptive mother dies at the scene. To probe into the matter, Tsz Kit returns to Hong Kong alone. With his best friend Tai Wah Koon pulling a few strings for him, Tsz Kit uncovers that his adoptive mother’s death is connected to Ling Hung, an Iron Lady running multiple syndicates, who is so powerful that her decision will lead to a profound impact on the economy and livelihoods of the communities. Her adopted son Kent Ling and his girlfriend Kate Wei are her think-tanks; whereas Ching Yan is her bodyguard. However, Tsz Kit's appearance turns their relationship upside down. Meanwhile, Ling Hung's affiliates are waiting for an opportunity to wreak havoc, putting her life in imminent danger. Though Ching Yan and Tsz Kit join forces to strike back, they trigger a new wave of bloodshed that is about to engulf the whole society.