In 2010, Senior Inspector CHEUK HOI from the Criminal Intelligence Bureau (CIB) of the Hong Kong police force heads to Bangkok, Thailand, commanding the covert agents he dispatched there to investigate a Hong Kong drug lord.

Due to their declining influence, NGAI TAK-SHUN, the son of NGAI CHUNG-SHAN who is the leader of a Hong Kong triad society, Cheung Hing, returns with a bang to take over the gang and starts cleaning house.

Having recruited a top hitman named CHAI FING, FOON-HEI goes to elaborate lengths to ambush TAK-SHUN, but the attempted assassination fails because TAK-SHUN, as a military veteran, manages to escape.

CHEUK HOI and SUK-MUI are performing surveillance in Thailand in hopes of finding those covert agents that are with FOON-HEI but they have lost contact with. At that time, it’s confirmed that one of PAK-KEY’s confidants is their lost covert ag

SIU-FUNG knows that PAK-KEY lost the drugs that were initially stolen by TIN-TONG, and the buyer is seeking revenge. To protect PAK-KEY, SIU-FUNG decides to secretly kill FOON-HEI.

TAK-SHUN and KA-LEI work together, using a high-end club as a façade to cover up their money laundering business; whereas SUK-MUI manages to land a job at the high-end club as a waitress, seeking to take the opportunity to investigate Cheung Hing