Line Walker

DING SIU-KA and her three foster mothers operate a foot spa together. She is also an undercover officer working for CIB chief inspector HONG TO-HANG. CHEUK HOI is TO-HANG's colleague. He is suspected of corruption and the ICAC is carrying out investigation on him. CHEUK HOI tries hard to find the dead body of his undercover officer and he swears that he will not let another undercover officer die. When he returns to the police station, chief inspector from the Organized Crime and Triad Bureau (OCTB) YIP SHIU-LEUNG provokes him. SIT KA-KEUNG appears to be an ice delivery worker but he is actually a member of an illegal betting syndicate. SIU-KA's foster mother is in debt and KA-KEUNG arrives to make trouble at their foot spa. SIU-KA tries to get the cash and the receipt for borrowed money from KA-KEUNG but KA-KEUNG discovers it. YAU TAT-FU, nickname Flounder, is a triad leader.… ...

KA-KEUNG is released. He immediately goes to the foot spa with his subordinate CHEUNG MUK-WING for he wants to get back the account record and name list from SIU-KA. TAT-FU praises KA-KEUNG and KA-KEUNG requests to be the person in charge of his illegal betting business. CHEUK HOI wants to get some important information from TO-HANG's computer but he doesn't have the password. KA-KEUNG tries to fight for the right to handle the illegal betting business and he is being chased. SIU-KA is embroiled in it as well. TAT-FU tries to mediate between the two groups and he suggests choosing the person in charge based on their profits. In order to find TO-HANG's undercover officers, CHEUK HOI attends his funeral. SIU-KA attends the funeral secretly and CHEUK HOI discovers her. SIU-KA passes CHEUK HOI's test and she becomes his undercover officer.… ...

MUK-WING is being cheated during betting. He tries to get back the money from his enemy but he is captured. Luckily, SIU-KA knew that KA-KEUNG will be in danger and she goes to rescue them. HO-KAN and FOON-HEI get to know each other in the prison. FOON-HEI is very upset to discover some prisoners trying to operate usury in the prison and HO-KAN tackles the problem. FOON-HEI is very pleased and he promises to offer works to him later. When TAK-FU tries to announce the result for operating the illegal betting business, SIU-KA arrives to help KA-KEUNG and KA-KEUNG wins eventually. SHIU-LEUNG tries to carry out investigation on the illegal betting syndicate but CHEUK HOI is not willing to cooperate with him. SHIU-LEUNG decides to get information from SIU-KA. HO-KAN is released from prison eventually and he starts working in a stock agency but two gangsters suddenly arrive to capture him.… ...

KA-KEUNG is invited by TAT-FU to attend a triad organization's banquet. As instructed by CHEUK HOI, SIU-KA brings a hidden camera with her to collect information but the camera is not working properly. FOON-HEI discovers HO-KAN giving his spoiled son a lesson and he asks HO-KAN to help managing his son. When HO-KAN returns home alone, he meets his ex-girlfriend SIN-YAN but SIN-YAN refuses to have contact with him. TAT-FU wants to be the triad leader and he asks his subordinates to kidnap FOON-HEI's only son. Both FOON-HEI's son and HO-KAN are being kidnapped. FOON-HEI's son is injured and he keeps bleeding. KA-KEUNG asks SIU-KA to help finding a doctor to treat him at the hiding place. SIU-KA informs CHEUK HOI immediately and CHEUK HOI gives SIU-KA a tracking device...

CHEUK HOI bursts into the hiding place with his subordinates but they fail to find SIU-KA and the others. CHEUK HOI discovers the whereabouts of FOON-HEI's son successfully based on the clues left by SIU-KA. TAT-FU calls his subordinates and asks them to kill FOON-HEI's son. SIU-KA tries to stop them and HO-KAN seizes the chance to make trouble as well. CHEUK HOI bursts into the place and they start a gunfight. During the chaos, KA-KEUNG and MUK-WING take FOON-HEI's son away. KA-KEUNG is being punished by TAT-FU for taking FOON-HEI's son away without informing him. SIU-KA believes that HO-KAN is TO-HANG's undercover officer as well. She sneaks into the hospital to look for him. However, she discovers FOON-HEI arriving to visit HO-KAN. HO-KAN finally reveals his real identity to SIU-KA and CHEUK HOI. In order to find the truth behind TO-HANG's death, the three of them decide to continue their investigation on FOON-HEI and TAT-FU.… ...

SIN-YAN suspects that CHEUK HOI is bribed by FOON-HEI and CHEUK HOI tries not to disclose the truth to her. FOON-HEI visits SIU-KA's foot spa on the election day for the gang leader. He then asks SIU-KA to be his spokesperson in a meeting with TAT-FU. FOON-HEI meets up with TAT-FU alone and he lures him to gain money from the stock market together. HO-KAN and SIN-YAN were lovers. In order to carry out his duty, HO-KAN has committed crime. SIN-YAN didn't know the truth behind and she decided to separate with him. HO-KAN helps TAT-FU to earn a lot of money within a short period of time. TAT-FU worries that FOON-HEI will harm him after knowing that he has kidnapped his son before. He tries to shift the blame to KA-KEUNG and he beats KA-KEUNG fiercely. SIU-KA brings KA-KEUNG to her foot spa for a rest and she makes excuse to gamble with him but she loses eventually.

SIU-KA loses a lot of money and she tries to take the money back by making KA-KEUNG drunk. However, she is drunk as well eventually. They end up sleeping together and SIU-KA's foster mother discovers it. SIU-KA has no choice but to claim that KA-KEUNG is her boyfriend. After breaking up with HO-KAN, SIN-YAN starts dating with SHIU-LEUNG. In order to gain trust from TAT-FU, HO-KAN goes to the night club with him but he meets SIN-YAN accidentally. In order to disturb FOON-HEI's illegal betting business, TAT-FU asks somebody to inform the police secretly. SHIU-LEUNG captures the whole team but he is not able to find any evidence against FOON-HEI. On the other hand, TAT-FU loses a lot of money from investments and the police is looking for him. The senior management of ICAC decides to suspend the investigation on CHEUK HOI but SIN-YAN tries to monitor CHEUK HOI even harder.… ...

In order to capture TAT-FU, CHEUK HOI carries out investigation at the warehouse and he is embroiled in a gangster fight accidentally. In order to rescue TAT-FU, KA-KEUNG fights against the gangsters with CHEUK HOI. FOON-HEI has established an unassailable position in the gang. He wants HO-KAN and KA-KEUNG to collaborate with each other. CHEUK HOI investigates the clues left by TAT-FU and he has new findings. FOON-HEI organizes a banquet for KA-KEUNG and other subordinates. SHIU-LEUNG suddenly arrives with a group of police officers and he brings SIN-YAN to HO-KAN deliberately. Senior management of ICAC asks SIN-YAN to stop her investigation on CHEUK HOI. SIN-YAN tries to air her grievances to SHIU-LEUNG and SHIU-LEUNG proposes marriage to her. SIU-KA's foster mother worries that KA-KEUNG will make SIU-KA die and she asks KA-KEUNG to separate with her. SIU-KA tries hard to speak for KA-KEUNG.… ...