FAI is a talented customs inspector. His performance wins him appreciation from his supervisor. He even arrests a smuggler who has swallowed drugs. Inspector LI is in charge of Investigation Bureau. FAI replaces LI who has been hurt when he is on duty. WA becomes FAI's subordinate but WA is not acquainted with FAI's working style. FAI insists on doing the work in his own way. KONG SAl YAN is a cigarette smuggler. He managed to escape after hurting LI. He wants to leave Hong Kong. FAI leads his team to check boats leaving Hong Kong. He u s e s pepper to force YAN to surrender.

FAI and WA bring YAN to the police station where they come across CHAN KIN MAN. MAN is not polite to them and he criticizes WA as a hot-tempered man who always tortures criminals. WA is discontented. At home, WA swears to arrest the black hand as his girlfriend was killed in a case of cigarette smuggling. KONG is sentenced eighteen-month imprisonment. FAI appreciates YI who is in charge of the accusation. WA does not give up. WA's colleagues convince FAI to open the file again. TSUI KONG tricks FAI and WA. He baits them to follow him. In the water, KONG wants to kill them with his boat.

FAl and WA fall into the water. WA is saved by FAl. After the incident FAl and WA realize that they should give up their bias and FAI is accepted by his team. FAI's cousin TUNG works in the restaurant of the customs officer. His wife KUEN looks down upon him. FAI suggests that TUNG should be a customs officer. KONG tricks FAI again, Though FAI can arrest KONG, he has no way to accuse KONG. FAI brings TUNG's son KIT to a book exhibition. There he meets YI and her adopted daughter MIMI. They enjoy the gathering. FAI wants to invite YI to dine with him but YI has to go and meet her boyfriend MAN.

KONG threatens PAUL to work for him with his mother's life. PAUL has to supply cigarette to KONG. In return KONG gives him money. MAN goes to have dinner in YI's house. He gives her four film tickets. As YI's mother cannot go to the cinema, YI gives one to FAI. Knowing that Yl has broken her favourite cup, FAl buys a new one for her. However YI comes with MAN and FAI does not have the courage to give it to YI. FAI and WA gather strong evident to prove that PAUL has been helping KONG. PAU is -arrested. KONG discusses with MARTIN after PAUL has been arrested.

PAUL tells FAI and WA what he knows about KONG. KONG is arrested. PAUL hears that his mother is on the brink of death in Malaysia. MAN is instructed to escort him to meet his mother but on his way, he is killed. KONG is set free. KONG contacts LIP TAl KWAN to be his new partner. They meet in Shengzhen. However KONG is not allowed to get close to KWAN. KWAN is killed but KONG does not know. FAI finds that TUNG looks like KWAN and he persuades TUNG to impersonate KWAN. TUNG gets into KONG's car and KONG's car soon disappears. From the receiver, FAI knows that TUNG is in a dangerous situation.

When KONG knows who TUNG is, he wants to kill him. FAI comes but he can do nothing as TUNG is in KONG's hand. WA grasps a chance to catch KONG. After solving KONG's case, FAI has to handle a new case, copying films without legal permission. SOR asks SING to record the film in the cinema. YI and MAN arrest SING when they know his illegal act. From SING's information, FAI arrests SOR. SOR is angry as SING has betrayed him. YI is discontented with MAN's style as he always flatters his supervisor. TUNG is appointed as a customs officer.

FONG faints in the street. She is saved by WA and JO. Later they buy illegal films from FONG. FONG asks them to leave their pager numbness. FONG contacts CHI who is the supplier and CHI promises to give her the films as soon as possible. CHI is beaten up by SOR's people. Luckily he is saved by PING. He works as a cleaner for PING. WA arrests FONG and questions her. However they cannot gather enough information. Later FAI uses secret codes and discovers that the films come from the same cinema. LAM KWOK WAI is the manager of the cinema. He loves his wife MUI, who is a paralyzed woman.

FAI tells WAI that the investigation has stopped. However WAI does not trust FAI. He asks PING to stop their cooperation temporarily. FONG is penalized and she dislikes WA. She meets some troubles and WA solve them for her. When WAI knows that FAI has used secret codes to identify his cinema, he adds some other codes to trick FAI. On the other hand, TUNG is sent to work in a quick delivery company. TUNG finds some films in a chocolate box. He informs FAI. They discover that the chocolate box has been mailed by MUI. They follow MUI to a factory building where she disappears. They can only find some films being left in a deserted unit.

WAI comes to the factory and meets FAI. WAI runs away, leaving behind MUI. MUI admits that the illegal business is run by her. Later she suffers from heart attack and is sent to hospital. Knowing that he will be promoted after getting married, MAN suggests YI to register their marriage and marry him later. YI is unhappy as MAN is to selfish. WAI wants to take MUI away but they meet YI at the door of the hospital. WAI drives his car at high speed and he loses his control of his car. His car falls down the cliff. MUI is killed in the accident and WAl escapes. FONG's younger sister runs away from home. WA helps FONG to find her sister. He also helps her to accept herself. WAI wants to avenge MUI's death by killing YI as he thinks that YI should be responsible for the accident.

YI asks for MAN's assistance but MAN claims that WAI will do no harm. He goes to Scotland with his supervisor and asks his subordinate to protect her. YI is discontented. FAI escorts YI and comes across WAI. They have a fight. FAI is hurt but in chaos WAI falls down and dies. YI gives FAI a gift to thank him. MAN returns and is jealous to see YI with FAI. He questions her but YI ignores him. FAI works with CHI for the case of forgery watches. NGOR gets some old photographs of CHI which were taken thirty years ago.

NGOR misses her husband and she goes to street. There she comes across CHI. Though it is a casual chat, special feelings are found deep in their hearts. CHI thinks that NGOR has got married. Later he learns that NGOR lives with her son and she had not got married when she gave birth to her son. He finds it strange. One day CHI sees NGOR and FAI in the street. He finds it suspicious. The next day, NGOR comes to warn CHI not to spoil her son's future. FONG persuades CHI to lead a new life. CHI meets his old friend MU. As CHI saved MU in the past, MU arranges a job for him in his watch factory. FAI is in charge of the case of forgery watches. MU is his target and he makes a plan to arrest the criminals.

WA orders watches from MU. MU is so clever that he hires another man to take his role. He is aware that he is being followed. YI is bored. MAN comes with a ring. Knowing his intention, YI decides to break up with him. CHI tries to stop SING from entangling NGOR and they have a fight. CHI's face is hurt and NGOR takes him to the doctor. CHI asks NGOR to have tea with him. As her waist has twisted, she does not go. CHI worries and he goes to visit her. FAI comes home and is shocked to know that CHI is his father. He drives CHI away.

FAI hates CHI and he determines to imprison him. WA tries to collect information of CHI from NGOR. JO invites FONG and WA to. attend a concert together. FONG and WA become good friends. FAI arrests CHI with no reason. CHI tries to forget his pain by drinking wine. In the toilet of MU's factory, CHI overhears that MU is the black hand of the illegal trade. He argues with MU. However WA comes and arrests them. FAI requests CHI to pay one hundred thousand dollars as bail. FONG goes to seek NGOR's help. NGOR gives him financial support. In the court, CHI is condemned guilty and he is trounced by MU. FAI knows that he has misunderstood CHI.

FAI knows that CHI is innocent. WA waits in MU's factory so as to arrest him as they know that MU has to take the mould away. MU turns up but WA fails in getting the mould as MU throws it away. TUNG's wife KUEN loses a lot of money in the casino of Macau. CHOI helps her so that she can return to Hong Kong. In the court, MU's lawyer accuses FAI being CHI's son. Luckily the judge condemns MU guilty as the mould is found. However FAI's duty is suspended and he is subject to internal trial. Being flattered by materialistic life, KUEN abandons her family elopes with CHOI.

TUNG decides to forget KUEN and bring up his son. FAI goes to search for the photograph in the heap of litter for YI. YI is touched. She realizes that FAI is better than MAN and she accepts him. FAI's foster uncle SHAN returns. SHAN treats NGOR and FAI good. FAI and YI come across MAN. They have a fight and it is taken by a journalist. In a gun fight, WA saves FONG and they fall in love with each other. FAI is transferred to clerical work. He chooses to resign. LAI invites him to work as a spy in a drugs smuggling gang.

As YI's good friend ANN has died of over-dosage of drugs, FAI decides to take LAI's appointment. LAI suggests FAI to approach WING, an ex-customs officer, as WING is a member of the gang. CHOI is discontented with WING who gets his share of profit in the drug trade. FAI is gradually accepted by WING. One night after gambling, WING is lurked by CHOI's henchmen. FAI risks his life to save WING. WING thanks him. He pays all FAI's debts and asks FAI to work for him in his karaoke. After discussing with LAI, FAI decides to lie to his family that he has to work in Taiwan.

KUEN suggests that they should break up. Knowing that KUEN loves CHOI more than him, he has to accept the request reluctantly. CHOI and WING have several gang fights. Their boss LI MAN KI settles the dispute between them. KI appreciates FAI's talent. WA is instructed to keep an eye on a drug smuggler. With the help of an infrared camera, he realizes the target he is following is CHOI. He determines to arrest CHOI. CHOI uses KUEN's car to transport drugs. When he knows that WA is following him, he escapes. KUEN and his henchman are arrested. KUEN is innocent but as it is her car, she is suspected.

KI brings WING and FAI to Thailand where there will be a drug transaction. In order to test FAI's loyalty, KI sends henchmen to impersonate policemen and take drugs from FAT. FAI tries his best to protect the drugs. He wins KI's trust. CHOI has to leave Hong Kong secretly. WA and TUNG go to arrest him. TUNG catches him so as to testify that KUEN is innocent. FAI takes a taxi-dancer to a motel as instructed by KT. He does so as he does not want KI to suspect him. However he meets YI at the motel entrance. YI is in despair. FAI gives YI a recording tape which states the reason of his behaviour. However YI does not listen to it.

WA follows KI's henchmen to the place where illegal transactions are done. He is discovered and KI gives order to kill him. FAI volunteers to shoot WA. He shoots at WA's pocket inside which there are some hard objects so as to save WA. WA is hurt and his colleagues hate FAI. YI finds the recording tape and realizes that FAI is working as a spy. In order to calm NGOR, YI tells NGOR her discovery. SHAN overhears the fact and he plans to get rid of FAI. Everyone is nervous and wants to know what will happen to FAI. Will he be killed and what will happen to SHAN? Don't miss the final episode in which all the questions will be answered.