Line Walker: The Prelude

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

Just as SUK-MUI is drugged unconscious by SMOKEY, TIN-TONG shows up. TIN-TONG teams up with SUK-MUI to sneak into the drug manufacturer and expose that SMOKEY reaped profit from selling blue ice on the sly, but they end up being hunted down by SMOKEY.

With CHEUK HOI’s help, SIU-FUNG manages to steal the drugs from TAK-SHUN’s warehouse, following which FOON-HEI instructs SIU-FUNG to hand the drugs over to CHAI FING. CHEUK HOI then tails after CHAI FING and learns the location where FOON-HEI keeps his drug

CHEUK HOI and CHI-BUN continue to investigate those corrupt cops who work for FOON-HEI. Unexpectedly, CHI-BUN is instead suspended from his duties after being falsely accused of misconduct for accepting advantages.

CHEUK HOI tenders his resignation to KAI-FAT, the senior management of the police force, and recommends CHI-BUN as his successor. After getting the blue ice drugs back, TAK-SHUN brings along KA-LEI to take part in the gambling tournament.

CHI-BUN asks YEUNG WING out to dinner to thank her for returning the wallet to him, and he has a very high regard for her because of her aspiration. With FIRECRACKER going against him, FOON-HEI sends SIU-FUNG to follow TART Q to take part in FIRECRACKER’s counterfeit money operation.

When SIU-FUNG and SUK-MUI sneak into SZE KA-LEI’s home, they encounter obstacles, so they immediately call CHEUK HOI for help. Later, CHEUK HOI analyzes the whole thing, thinking that someone wanted to harm KA-LE

SUK-MUI and TIN-TONG start doing the money laundering business for TAK-SHUN, but TIN-TONG starts getting suspicious of SUK-MUI. On top of that, he even tracks her down to the safehouse.

CHEUK HOI, out of empathy, tries to convince KA-LEI to leave TAK-SHUN, keeping herself away from the criminal activities, to which KA-LEI has no comment.

The Commercial Crime Bureau(CCB) suspects that Ling Chi Finance Ltd. is involved in money laundering activities, and SUK-MUI is taken back to the police station for questioning. Having heard this, MR. WHITE starts pressuring TAK-SHUN.

MADAM CHEUNG finds CHI-BUN and assigns him a secret mission. FOON-HEI is told to meet up with MR. WHITE somewhere, however, upon his arrival, he runs into a mystery woman called LEUNG SZE-MAN.

SIU-FUNG learns that FOON-HEI is going to deal with the police, so he immediately informs CHEUK HOI about it. Knowing that he is unable to stand by KA-LEI’s side, CHEUK HOI resign

CHEUK HOI tries to enlist the help of those who are able to take over the challenges of the criminal intelligence operations through the profiles of those ex cops, including a former female cop, LAW SIU-SZE, a device-maker, SHEH LOK-SHING and an impersonator LEE MAN-HUNG...

With CHEUK HOI leading his men to meet up with the fourth covert agent, the corrupt cops scheme to catch them all. KA-LEI notices there is a large cash transaction in Ling Chi, so she tracks it down to SZE-MAN.