SAMANTHA SUNG is a Chief Inspector of the Police Counter-Terrorism Unit (CTU). Brainy and attractive, cool-headed and decisive, she has numerous achievements to her credit. YIU LAI FA, a helpful, unconstrained and upright police officer, vows to eradicate the terrorists. Constrained by her low rank, YIU is still waiting for her break. FA eavesdrops on the conversation of a couple in a fast-food restaurant. The tearful woman asks to break up with the man for fear that his future will be bogged down by her work. FA feels sorry for her hard decision. Later, she is introduced to her new colleague in the unit, BO BO TONG, the same woman she met in the restaurant. BO BO, lively and cheerful, is radically different from her former distressed self. FA sees her new colleague in a new light. FA and BO BO are harassed by some patrons in a bar, but SAM timely comes to their rescue. The incident strengthens the bond between the women.… ...

SAM and her team have launched a raid on the terrorists. Though she has saved an innocent car dealer DAN LI, who trespasses upon the scene, from clear and present danger, and has arrested members of the terrorist group, some of the collaborators manage to flee. In view of the imminent threat of terrorist attacks, SAM seeks to strengthen her squad by enlisting FA and BO BO. SAM’s stern attitude at work instills fear in her new colleagues. Yet outside work, SAM reverts to her easy-going nature, and even accompanies FA and BO BO for a few drinks in a bar. The trio joins hand to teach a lascivious man a hard lesson. FA and BO BO quickly dismiss their resentment of the boss and become bosom friends with her. DAN is conducting business with a potential buyer when FA seizes his car to pursue a suspect. An ensuing gun battle wrecks the car and costs DAN his job.… ...

Following the successful anti-terrorist operation, FA and BO BO return to their respective posts in the police. But FA misses her work in the CTU. When SAM invites FA and BO BO to join her squad on a permanent basis, the two lose no time to jump aboard and begin their training. A guilty-stricken FA tries to offer DAN help but blunders her assignment. DAN is convinced that she will bring him ill luck. SAM remains a close friend of her ex-boyfriend, JOE YEUNG, Chief Inspector of the Intelligence Unit, though JOE has a new girlfriend SUSAN FONG, a school teacher. Tycoon BEN LIN colludes with overseas gangs and terrorist groups in order to consolidate the leading position of his diversified business empire. But he is dealt a heavy blow when the Immigration Department seizes his drugs. BEN suspects that an undercover cop has informed on his drug trafficking and dispatches an assassin to get rid of the informer.… ...

BO BO is mistaken by the parking assistant QUICKIE SZE as a prostitute during an operation. QUICKIE falls in love with her at first sight and begins his courtship of BO BO despite her undignified profession. SAM has ascertained that BEN is involved in a missile trade with an arms dealer and is responsible for the ruthless murder of the undercover cop. In an attempt to collect evidence of his crime, she arranges for FA to work in his company to get close to the boss. DAN is plagued by a serious of setbacks: first, his creditors show up at his doorstep, then his live-in girlfriend has dumped him, and worse still, the bank has seized his flat following his failure to pay the mortgage. DAN finds himself ending up in the streets. Reduced to destitution, DAN chances on his primary school friend QUICKIE.… ...

FA tolerates the sexual harassment of her superior TSE HO SHING in order to accomplish her tasks. DAN and QUICKIE chance on FA and BO BO, and DAN immediately recognizes them as police officers. QUICKIE is stunned. FA sneaks into BEN’s office to gather evidence but nearly gets caught by the boss, but FA keeps her wits and manages to extricate herself from immediate danger. SAM often seeks JOE’s advice on discouraging the unwanted attention of her suitors. As usual, SAM pours out her everyday troubles to JOE. Acting in a moment of impulse, the old lovers sleep with each other. Though JOE is eager to rekindle his love with SAM, SAM believes it was no more than an impulsive act and keeps her distance. In order to bring FA closer to BEN, SAM seeks to learn about his likes and dislikes from his ex-girlfriend. Her plan works. FA has attracted the attention of the boss, who becomes smitten by her and has taken the initiative to approach her.

FA feigns that she accepts BEN’s courtship so as to collect evidence to convict him. QUICKIE declares his love for BO BO and persists with his courtship despite her rejection. BO BO consoles FA for the grievances she has to bear as an undercover police. One day, FA and BEN go on a date and chance on DAN. Afraid that her identity will be exposed, FA makes DAN pose as her ex-boyfriend by hook or crook. But DAN’s masquerade only serves to arouse BEN’s skepticism. SAM notices that BEN has held FA in suspicion and orders her to abandon the operation. But FA refuses to rest her case unless she has gathered evidences to nail him down. SAM gives her consent reluctantly. The distrustful BEN has found out that DAN’s ex-girlfriend is in fact a girl named SHIRLEY, and not FA. On the other hand, to verify the suspicion that FA is an undercover cop, BEN has deliberately divulged to her the place where the missile trade will be conducted.… ...

Though FA is the embodiment of his ideal partner, BEN cannot afford to keep an undercover police in his rank and orders her assassination. SAM and BO BO rush to save FA out of danger. With his dealing place exposed by the police, BEN destroys the missiles and blasts away evidence of his crime. The police fail to convict him of arms smuggling due to the absence of evidence, but has successfully brought a charge of business fraud against him. To fill the void in FA’s personal life, SAM arranges for her to go out with a host of handsome guys. JOE is struggling to forget SAM since the episode and seeks to bring his forlorn hope to an end by proposing to SUSAN. SUSAN accepts his proposal. BO BO often takes advantage of FA’s generosity, and even moves into her apartment. In order to get close to his object of affections, QUICKIE puts his life savings on renting a flat opposite to FA’s.… ...

BO BO finds the affection and care shown by her new neighbor immensely annoying. QUICKIE even digs through her trash in order to learn more about her daily habits. As the day of their wedding approaches, SUSAN summons the courage to tell JOE that she is not ready to marry him. JOE is devastated by the aborted wedding. DAN is tempted by his friend’s invitation to become an active shareholder of his motors company. He tries every means to raise the money for the investment. Again, a vexed SAM confides her love troubles in JOE. This time, JOE suggests that they see a shrink together. BO BO decides to turn QUICKIE’s harassment to advantage and makes him run errands like a slave. Indignant at BO BO’s exploitative labor of QUICKIE, FA cautions her friend, but BO BO will not listen. DAN has picked up FA’s passbook by accident and realizes that the young woman is in fact very well-off.

The CTU has established the link between the series of anthrax poisoning with terrorist attacks. SAM is put in charge of the investigation. KAM CHI HUNG, staff of a research institute in Japan, is the culprit behind the series of the anthrax attacks in his attempt to extort money from the Hong Kong Government. SAM and JOE are told by the shrink that they both suffer from the same trauma in love relationships and the best cure is for them to revert to former status as lovers. Driven by the greed and eagerness to start up his own business, DAN schemes to con money out of FA with the false promise of love. BO BO mistakes the waiter at the diner LI TSIN TSUN as a swindler. When she realizes that it has been a misunderstanding, she offers her apologies and volunteers to be his son KIN’s tutor to make up for her mistake.… ...

After a wild chase, HUNG is arrested. SAM interrogates him for the location where he puts away the anthrax virus, but he seals his lips. TSUN is happily reunited with his mainland wife AH PING, who has successfully applied for the right of abode in Hong Kong. He also introduces her to work in the diner so that she can take care of KIN. Yet she has attracted the unwanted attention of TSUN’s boss CHEUNG, who harasses her at work. PING is deeply troubled by his advances. DAN goes after FA aggressively and even meets her father YIU YING BIU in her home village. DAN impresses FA with his bold confession in front of the father. CHEUNG forces himself on PING when she is checking invoices in the storeroom. PING pours her grievances to TSUN. Enraged, TSUN seeks to settle scores with CHEUNG. But PING, overwhelmed with humiliation during their confrontation, darts into the street where she gets knocked down by a reckless driver ROBERT.… ...

CHEUNG fires TSUN following the death of PING. TSUN nurses a grudge against the boss and is convinced that ROBERT has collaborated with the villain in PING’s murder. When CHEUNG and ROBERT subsequently die from anthrax infection, SAM believes the territory is hit by another weave of terrorist attacks and launches a full investigation. She cross-examines HUNG, believing that his collaborators are behind the outbreak. It turns out that HUNG has hidden the test tubes containing the deadly virus among KIN’s belongings amid the police’s pursuit. TSUN has discovered them by accident and decided to use it to kill CHEUNG and ROBERT to avenge PING’s death. FA goes on a date with DAN. She feels so blessed and thankful to his love and care. JOE confides in SAM his troubled relationship with SUSAN. Their friendly embrace turns into a sexual one.… ...

Despite their sexual relationship and cordial friendship, SAM reiterates to JOE that it is better for them to remain ordinary friends. TSUN contaminates the office of the Social Service Department with anthrax, which results in the infections of several of their staff. Again, SAM tries to seek out the culprit by interrogating HUNG, but HUNG proves his innocence. DAN feels drained and exhausted by FA’s tricks. QUICKIE advises DAN to give up, but DAN remains resilient. BO BO investigates into the outbreak and reveals TSUN to be the culprit behind the anthrax attacks. She urges TUSN to turn himself in, but he flies into a threatening rage and defies her accusation. Armed with the anthrax test tubes, TSUN appears at the court during the trial of KIN’s child abuse case. He demands the immediate release of KIN by threatening the social service staff with the deadly virus.… ...

Dan can tolerate the spoilt lady no longer and asks to break up with her before further damage is done. FA is heartbroken to learn of his real motive, for she has fallen in love with him. Nonetheless, the two reconcile and become bosom friends. To transform himself into an eligible suitor, QUICKIE seeks to better himself by quitting his parking job and striving to climb up the social ladder through education. Deep down, JOE has harbored the desire to rekindle his love with SAM. Without his knowing it, he has detached himself from SUSAN in order to woo SAM. He even obstructs SAM’s dates with other men, but his intrusiveness gets on SAM’s nerves. QUICKIE’s sincerity moves BO BO, and she finally agrees to go out with him. SAM has gathered the intelligence of a planned assassination of the president of a foreign country LAMIYE during his forthcoming visit to Hong Kong.… ...

SAM has appointed FA to take charge of the protection of LAMIYE during his visit in the territory. The failure of LAMIYE’s bodyguard LI TIN WAH to provide FA and her team with the president’s itinerary results in a delay in their deployment. SUSAN is puzzled by JOE’s aloofness and seeks SAM’s counsel. DAN’s chance meeting with SAM ignites his admiration for the heroine, who has left her mark by courageously saving his life in peril. DAN begins his courtship of the woman. BO BO is prepared to tell FA and SAM about her relationship with QUICKIE, but not before FA voices her concern of his womanizing and untrustworthy nature. Daunted by the critical remarks, BO BO refrains from divulging the secret. SAM lies that DAN is her new boyfriend in the hope of stopping JOE’s pestering once and for all, but JOE remains skeptical. Despite the security measures installed, the assassin strikes at the president.… ...

SAM has taken the initiative to show DAN her affections. The overjoyed suitor credits the successful courtship to his devotion and sincerity. FA questions WAH’s attitude at work and often gets into arguments with him over their work arrangements. During an operation to protect LAMIYE, WAH risks his life in saving FA. FA begins to see WAH in a new light. JOE’s constant pestering has finally led BO BO and FA to realize that JOE is caught between two lovers, SAM and SUSAN. WAH’s mission has come to an end, following LAMIYE’s departure. Before he leaves the territory, he has specially visited FA to say goodbye. SAM goes out with DAN, hoping that JOE will be awed by the futility of his love and withdraws. DAN brings SAM to meet SHIRLEY and brags about her new girlfriend. Unable to forget DAN, FA tries to learn about his latest happenings from QUICKIE. But the news of DAN’s seeing someone new, SAM, leaves a sour taste in her mouth.

DAN has unwittingly learnt about the affair between QUICKIE and BO BO. He is trying every means to make them reveal their relationship. FA fears that DAN will be devastated by his unrequited love for SAM and resolves to tell him the truth. Though DAN is well aware of SAM’s real motive, he is willing to lend her a hand in stopping JOE’s pestering. His devotion finally moves SAM, who repays his ardor with love. FA is agonized by their affair. WAH has returned to Hong Kong to find himself a new job. He musters up his courage to declare his love for FA, who is distressed by her forlorn love for DAN. BEN has served his time and walks out from jail a free man. SAM has always borne a grudge for failing to convict him with arms smuggling. She contacts a witness MATT to extract evidence against BEN, but MATT has instead lodged a complaint against the CTU for extorting false evidence against the defendant.… ...

WAH has paid a visit to the maid SISTER LUK, who raised him up as a child. He has narrowly missed DAN, who has also dropped by to visit LUK at around the same time. MATT’s incongruous testimony is jeopardizing his chance of winning the case against BEN. WAH expresses his affections for FA, but FA is unimpressed. DAN becomes emotional when he learns that WAH is wooing FA. Years ago, WAH abandoned his friends and family in Hong Kong to pursue his goals overseas without their knowledge. DAN is still upset with his irresponsible departure. The boss of the motors company MR CHEUNG has offered to sell off his business to DAN. In raising money for the purchase, DAN demands WAH to return his share of down payment made on a flat they once co-owned. But DAN is hugely disappointed to learn that CHEUNG has already sold his business at a high price to another buyer.… ...

FA asks WAH to keep her role in sealing DAN’s business deal a secret. DAN is exhilarated to officially take charge of the motors company. He calls FA, and breaks the good news to her at once. WAH has secretly divulged BEN’s moves to SAM. She wonders about his real motives. Unable to bring herself to face DAN, FA has chosen not to attend the grand opening of the motors company. Her absence bewilders DAN, who fears that she might have met with an accident. DAN’s attitude toward FA strikes SAM that he has fallen in love with her subordinate. JOE asks to make up with SUSAN, who accepts his proposal. FA explains to DAN the reason behind her evasiveness. Only then he knows that FA has been in love with him secretly. BEN seems to be well informed of the operation of the CTU. As SAM investigates into the information leakage, she finds out that a subordinate FELIX has been spying for the seasoned criminal.… ...

DAN waits anxiously as FA is undergoing life-saving operation for the gun wound she has received. Though FA was shot at close range, BO BO believes that the shooter has in fact played mercy by aiming at her bulletproof jacket. BEN colludes with a foreign gang to assassin SENATOR JONES in order to claim governance of a special administrative zone of a foreign country. Capitalizing on WAH’s impressive portfolio as a bodyguard, BEN assigns him to head the mission. SAM meets with WAH, who reveals the reason behind his cooperation with the police. WAH in fact works as an undercover detective for a foreign organization to spy on the notorious criminal. To DAN’s relief, FA has undergone a successful operation. WAH’s identity is exposed during the failed assassination of JONES. To flee from Hong Kong, BEN has taken WAH and DAN hostage and uses them as human bombs.… ...

WAH defuses the bombs and saves the men’s lives. Caught between two women he loves, DAN is unable to make up his mind. DAN has moved into WAH’s apartment to avoid seeing the two women altogether. But with his whereabouts revealed, DAN is pressed to make a choice. Despite his best efforts to please BO BO, QUICKIE fails to win her heart. Tormented by his unrequited love, he asks to break up with her. The experience of being dumped leaves BO BO with distaste. Facing their share of troubles in love, SAM, FA and BO BO decide to drown their sorrows in food and wine. Before WAH’s departure, he asks DAN to handle his delicate personal relationships with care. After long agonizing thoughts, DAN resolves to leave his fortune and romance to destiny.