Against the backdrop of neon lights in Hong Kong, there is a hidden dark side that nobody knows - the city is the hub of narcotics from all over the world. Rewind ten years and Narcotics Bureau has apprehended Man Wah, aka Drug Lord
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.
Sergeant Ko Fai completed undercover operations many years ago, and there is always a cloud hanging over him. Ko Fai is reassigned to a police precinct that is Crime Squad Station Sergeant Fong Chi-kiu’s territory. While investigating cases, the duo gradually familiarize with each other and develop tacit understanding. Chi-kiu is so dedicated to her job that she has no time for taking care of her family. Her son hangs out with the wrong crowd and gets into trouble. Hotpot restaurant lady boss Lo Sin-man was naive when she was young as she slept with gang boss Law Wai and gave birth to a girl called Lo Siu-po. Fortunately, Ko Fai has always taken care of Sin-man and her daughter. Siu-po becomes a KOL and wants to step into the spotlight by engaging in reckless maneuvers. She gradually descends into the abyss as she reveals how drug dealers go about their business. To protect their loved ones, Ko Fai and Chi-kiu become guardians of the night and are determined to eradicate the villains!
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.