The story begins in the early 20th century, when policeman Sergeant TSU teams up with comprador Mr. KING in the arrest of a thief in Hong Kong. The victim of theft, ROBINSON, is happy to recover the stolen painting and decides to get the duo a portrait of themselves as a token of thanks. During the painting session, TSU and KING keep staring at each other with a hostile expression… The story moves into the present day with the TSUs being pestered by a broadband services salesman. The head of the family TSU HON-FEI is very unhappy with the salesman and tries to scare him off by boasting about his strong police family background. The salesman can tell immediately that FEI’s eldest son KWOK-ON and his second son KWOK-LEUNG are not policemen. Actually SIU-LAI, the youngest daughter of FEI, is the only family member who serves in the police force……

After a thorough investigation, HANG and his team discover that the prime suspect CHEUNG WAH-CHIU was actively involved in the electioneering campaign for KEUNG years ago during the District Council Election, which makes them believe that KEUNG is perhaps trying to return the favor by providing CHIU with an alibi. POK’s aunt KING CHI would like to match him up with a girl but the girl’s background does not really meet the expectations of his parents KING YIN and TSEUNG WAI-CHU. To find out why KEUNG did not hear the shots, HANG and LAI go to consult POK at his laboratory. POK agrees to offer help and has a site visit with them. HANG’s team finally manages to crack the case, which gives KIU a great thrill. To express her appreciation for her staff and POK, KIU invites them to a barbecue party at her mansion……

LAI is questioned by HANG and MAN PAK-CHU following the sudden disappearance of the fingerprints. HANG and LAI go to the university to consult POK again. Knowing that POK only sees the matter as a fun game to play, LAI gets a little irritated as she will have to rely on his findings and analyses to prove her innocence. POK conducts an onsite investigation, during which he seems to be quite interested in a bundle of electric wires which run through the property office. Inspired by a series of incidents, POK can finally solve the intriguing puzzle. LAI treats POK to dinner at a famous Chinese restaurant, after which they go back home individually. On her way to the MTR station, LAI spots POK eating spaghetti inside a western restaurant. The murderer is finally arrested and HANG offers to treat his staff to a celebration supper……

Someone warns on the Internet that the Hong Kong Convention and Exhibition Centre will be bombed real soon. To avoid any possible eventuality, the Regional Crime Unit is put in charge of the security operation around the Centre. LAI who is on duty inside the Centre is shocked to hear that POK is the winner of the Outstanding Achievement Award in Physics. It is not until this point that she comes to realize that POK is an internationally renowned physicist. While watching a football match on TV, HANG gets a call from a taxi driver, who is taking KA’s Brazilian friend RACHEL to his home. HANG is so captivated by RACHEL’s beauty and vivacity. He needs to keep reminding himself of her relationship with KA so as to resist her seduction. The 3-year-old CHAN CHI-MAN is suspected to have been poisoned, and LAI is assigned to handle the case……

Accompanied by HANG and his staff, POK and a team of research assistants have arrived with a full set of equipment to carry out a thorough investigation at the reportedly haunted apartment. LAI and POK bring MAN to an ophthalmology center for an eyesight test, through which they find that the boy is able to see the light which cannot be detected by ordinary human eyes. Curious to know whether MAN can really see the dead, LAI and POK go to Lantau Island to look for a Taoist priest. On their way back, the pair get lost amid heavy rain. In the confusion, LAI trips and twists her ankle. Due to the geographical isolation of the area, they get very poor mobile reception and can hardly seek help by phone. POK takes LAI to a pavilion nearby so that she can have a rest. The following day, POK is shocked to discover that LAI has fallen unconscious due to the serious inflammation of her hand wound……

LAI goes out for dinner with ON and his family, during which an acid-filled bottle suddenly falls onto the street and injures a number of pedestrians. HEI attends an admission interview with an elite school. Although he has made quite an impression on the principal, he is not selected in the end because of his parents’ poor performance. LEUNG finally manages to convince LAI to consult POK for him, although POK has turned him down already some time earlier. A conference has been postponed, so POK can find time to help LEUNG. He suggests conducting a series of experiments to collect more data, but would need an assistant to help with the process. LEUNG is not available for the tests, so LAI offers to be POK’s assistant on the experiment day. HANG and his team suppose they have arrested the prime suspect for the acid attack, but their guess turns out to be all wrong. POK manages to prove LEUNG’s innocence with his expert analysis……

The Rural Patrol Team has found some balloon debris in a tree around the hilltop. HANG and LAI go to the university to see POK. They bring along the climate data recorded on the day of the acid attack so that POK can have a clearer picture for analysis. LAI notices that there is something wrong with ON and SHEUNG. For the sake of HEI, ON would like to team up with his friend to tender for a catering contract with the university. Knowing that her brother and sister-in-law are in need of capital for the project, LAI offers to lend them money straight away. Based on POK’s analysis, the police decide to conduct a large-scale questionnaire survey in Tai Kok Tsui. LAI arrives at a rooftop squatter, where she meets a young man called CHEUNG HON-CHEUNG. After the onsite investigation and a thorough analysis of the survey data, the Regional Crime Unit identifies CHEUNG as one of the prime suspects… The case is finally solved……

With the help of his mates, HANG finally manages to locate PHOENIX, the girl who is believed to have slept with him. When HANG catches sight of her face, he gets a little horrified… No secret can be kept forever – FEI is furious to learn that ON and SHEUNG are planning to start a business of their own. Knowing that the rest of the family are all supportive of ON and SHEUNG, FEI begins to have a change of heart. POK suffers an acute of diarrhea after eating at ON’s cafe, making LAI and her brothers extremely worried. LAI and LEUNG offer to drive POK home. LEUNG feels sick and asks to use the toilet inside POK’s mansion. While leaving, LEUNG spots a painting in POK’s dining room, which looks exactly the same as the one at his home. CHI learns of this somehow and breaks the news to her family. A senior member of the KINGs, Uncle GEORGE urges CHI to acquire the painting from the TSUs as soon as possible……

KWAN-LEUNG’s parents come to the police station to see HANG. They insist that KWAN-LEUNG’s death is not a coincidence but the result of a conspiracy. LAI and PAK-CHU go to see CHOW HUNG, the fortune-teller who practiced divination for KWAN-LEUNG before his death. To their great surprise, HUNG is actually the father of CHOW SAI-YUE, a very good friend of KWAN-LEUNG. While performing a Taoist ritual for the dead in the suburb of Yuen Long, a group of citizens are shocked to find a mysterious tool box under the ground, inside which are some bullets and appliances. HANG goes to question YUE at the hospital and YUE admits killing KWAN-LEUNG almost straight away. Although YUE has confessed to the murder, the way how he killed KWAN-LEUNG still remains a secret……

The scientific journal allows POK a one-month grace period to prove his theory. Due to the limited time available, POK has to choose two from the four test methods for his experiments. LAI gets an SMS from POK while resting at home in the middle of the night. Knowing that he has not had dinner yet, LAI offers to buy him something to eat. After a good rest, KA goes fishing with HANG, during which HANG unveils his plan for the future for the very first time. Later in the night, KA spots HANG flirting with a girl in Lan Kwai Fong, which irks her no end… HANG and KA spend the night together. By the time HANG gets up the following morning, KA is gone already. Inspired by LAI, POK changes the order of the experiments, which eventually brings him the research results he needs. POK flies to New York for an oral defense of his theory. While staying at the hotel, he begins to surf the Internet looking for LAI’s information……

LAI cannot believe that POK is in love with her. To make sure he has really made a declaration of love to her, she decides to double-check with HEI. LAI gets dressed up for her first date with POK. She asks POK how he fell in love with her, and POK explains that it is all about the influence of phenylalanine. A badly burnt body is found in Kam Tin and the victim is an active gang member called KAM TAI-PANG. LAI and PAK-CHU try to gather more background information about PANG from the Anti-triad Unit, from which they learn that PANG used to be very close with a hairdresser named KONG YIU-CHO. Based on the data of PANG’s Octopus smart card and credit card, the police have worked out the approximate time of the murder. CHO was watching a football match at a pub when PANG was reportedly killed, which serves as a very strong alibi for the guy. HEI gets bullied by his classmate……

Keen to prove HEI’s innocence, LEUNG dashes around the park to look for witnesses. As the Regional Crime Unit is busy investigating the burnt body case, a minibus driver suddenly comes along with a major piece of evidence, based on which the police manage to locate the lethal weapon at the bottom of the cliff. HEI gets bullied at the school again. Desperate for a shield to protect himself, HEI decides to reveal the relationship between POK and LAI, hoping that this will scare off his classmates and cease the bullying. YIN and CHU ask POK about his relationship with LAI, and POK admits that they have been dating for quite a while. Having reviewed the evidence carefully, POK becomes a little skeptical about CHO’s alibi. Now that they have a new angle for investigation, LAI and her colleagues start to make progress with the case……

POK suggests having dinner with the TSUs at their home to celebrate the Ghost Festival. None of LAI’s family members has good table manners, which embarrasses LAI immensely. POK brings LAI to the restaurant to enjoy a meal with his family. CHU does not show up claiming that she has a terrible headache and needs to take a rest at home. CHI means to treat LAI coldly and refuses to talk to her all through the meal. POK accompanies LAI back to her home but gets involved in a car accident along the way. The TSUs and the KINGs meet at the Emergency Room but this first encounter between the two families turns out to be a total disaster. CHI asks LAI out for tea. On the surface, she seems to be offering an apology to LAI but in reality, she is trying to humiliate the girl with a flurry of scornful remarks……

LAI and her teammates have finally found the source of the cash, according to whom, the two HK$1,000 banknotes have been passed to WONG CHI-BUN, the yoga tutor recently hired by his company. The Yau Ma Tei Neighborhood Welfare Cooperative has won the fundraising campaign for the Chinese Charity Gala with an additional donation of HK$4,000. As the chairman and core members of the Cooperative, FEI, ON and LEUNG are invited to the TV station for a visit and the award presentation. CHI who serves on the Board of Directors for the Charity invites CHU to be one of the award presenters. FEI and his sons run into the KINGs in the dressing room… HANG goes to consult POK again, who later manages to find some clues from the bomber’s call. HANG has identified those who studied Mechanical Engineering in Australia as the likeliest suspects……

If the bomb cannot be defused or removed, the police will evacuate all the medical staff from the operating theatre ten minutes before the expected explosion. HANG and his team go to have a word with BUN asking for instructions on how to defuse the bomb, however… HANG gets a call from KA advising that she is coming back to Hong Kong soon, which makes him believe that the girl is going to press him to confirm their relationship. In fact KA does not come for HANG but her existing boyfriend ADRIAN, who has reportedly gone missing for quite a while. Knowing that KA is in a new relationship, HANG gets a little upset. POK is happy to be able to celebrate his birthday in Hong Kong, and suggests having his birthday dinner with his own family and the TSUs. CHI invites Uncle GEORGE to POK’s birthday dinner without letting him know……

HANG goes for a pint with his mates again. While talking about how obsessed KA has become with ADRIAN, HANG spots the guy in the pub flirting with a sexy woman. A resident in To Kwa Wan reports witnessing the kidnap of a young couple in the middle of the street. LAI manages to locate the residence of the couple. Not long after, the male victim, HUI TSUN-BONG, returns home with serious injuries. He insists that he was not kidnapped but only taken to see his creditor. When asked about the whereabouts of his girlfriend TSE YUEN-YEE, also the female victim, BONG starts prevaricating. LAI goes to the university planning to have lunch with POK, but is rejected. BONG accompanies YEE back to her home early in the morning. After YEE has left, a few husky men turn up suddenly with knives and swords in a deliberate attempt to injure BONG……

PAK-CHU and his subordinates get into the TSE Village to look for WAI, but are shocked to learn that BONG and YEE have gone missing again. The sudden disappearance of the lovers induces deeper misunderstanding and a further dispute between the residents of the two villages. HANG has a meeting with the representative of the North District Office, from whom he finds out that the long-standing conflict between the HUI Village and the TSE Village actually stems from the threat of a curse. Filled with doubts and questions, HANG decides to consult POK again. To solve the riddle of the curse, POK brings a team of university researchers to the TSE Village to collect samples for rigorous scientific analysis. YEE who suffers from acute abdominal pain goes to have a check-up in the hospital but runs into WAI along the way unexpectedly……

FEI makes a call to POK revealing how LAI gets blamed for injuring one of Uncle GEORGE’s guests while catching the alleged criminal. POK is perplexed by all the recent happenings and decides to go to Thailand for a relaxing holiday. To prevent any kind of hassle, he has left his cellphone off all through the trip. It is not until his return to Hong Kong that he comes to know that CHU has been sent to hospital for an urgent operation following an acute heart attack. After some serious consideration, POK gives LAI a call in the middle of the night asking her out for a word. POK decides to break up with LAI, leaving her completely lost and devastated. With no one else to turn to, LAI has no choice but to ring HANG up for help and comfort… CHI pays CHU a visit, during which YIN reveals that POK has already broken up with LAI. This piece of news comes as a really nice surprise to the ladies……

A young lady called KAREN reports to the police that her friend FION has gone missing mysteriously. She suspects that FION has been killed by her separated husband STANLEY, who is a specialist in Psychiatry. According to STANLEY, FION’s personal life is a complete mess and the girl is actually a heavy gambler deep in debt. HANG goes out for a drink with his mates. One of his friends has found a new girlfriend in the pub but the girl becomes attached to another man within just a few minutes. HANG is shocked to the core when he discovers that it is ADRIAN who has been flirting with the girl… HANG who is going to pursue KA realizes that he has never got to know her well. HEI gets bullied again at Windsor. His classmate makes insulting remarks about LAI, which irritates HEI so much that he strikes the boy and throws him to the ground. KAREN has discovered a lot of hidden pinhole cameras at home……

To free KAREN from stress and anxiety, SIMON decides to bring her to Lamma Island for a short stay. All of a sudden, STANLEY turns up again in front of KAREN, which gives her a terrible fright. SIMON has gone missing, so KAREN rushes to STANLEY’s office to look for him at once. KAREN becomes too angry with the doctor that she starts attacking him. HANG notices how quick and agile STANLEY is when he gives KAREN a local anesthetic injection. The Regional Crime Unit identifies STANLEY as the prime suspect but the man has already made his escape by then. To ensure KAREN’s safety, the Regional Crime Unit has arranged for different members to watch over her day and night. Despite this, STANLEY is still able to locate KAREN and abduct her from the hands of the police. POK manages to trace the whereabouts of KAREN in the nick of time, and surprisingly… As a token of thanks, HANG invites his staff and POK to a barbecue party……

LAI makes a formal apology to KIU for applying for transfer again shortly after her resumption of duties. CHI gets to know CHOY PO-YEE, the daughter of a local tycoon at a charity party. CHI is so impressed by YEE’s beauty and aura that she decides to match her up with POK. LAI’s successor WENDY is described as a big eater, and this is probably the only impression her colleagues can get of her. HANG starts wooing KA but gets no response at all from her. YEE goes to visit POK’s laboratory, during which she makes no secret of her admiration for the scholar. POK, however, points out clearly that he is not yet ready for a new relationship and rejects her right away. On the surface, YEE seems to be a refined, well-mannered lady but deep down she is nothing more than a selfish, hard-hearted hypocrite. KA returns to Hong Kong from a business trip and would like to give ADRIAN a surprise by paying him a sudden visit……

The radio-controlled helicopter explodes all of a sudden and everyone on the spot is knocked to the ground by the momentum. The ransom has been taken away, shortly after which an anonymous post appears on the Internet warning that a video clip titled “Embarrassing Moments of the Prince’s Army” will soon be disclosed. LAI and her supervisor have a meeting with a major sponsor to discuss the arrangements for the police’s annual fundraising event. The sponsor is a local charitable foundation, whose executive director happens to be YEE. Knowing that LAI is POK’s ex-girlfriend, YEE means to tease her in a most disgraceful manner. While KA is fishing alone by the seaside, HANG turns up suddenly. Not long after, ADRIAN comes along as well. HANG proposes to KA, which irritates ADRIAN so much that he gives KA a good telling-off for cheating on him. KA reveals to HANG that she will have to stay in Macau for work every other day……

TIN invites POK and HANG to the re-opening ceremony of one of his buildings which was destroyed in the explosion some time ago. POK discovers that there is something wrong with the stage setting when TIN is about to perform the ribbon cutting. With POK’s timely warning, HANG manages to stop TIN and saves him from getting an electric shock. POK has got a strange email but does not take it seriously. HANG goes out for a drink with his mates. Knowing that the pub owner is marrying a floozy, HANG and his friends become so surprised and even start to question his decision. HANG’s friends doubt if KA, just another notorious floozy, is an ideal wife for HANG, a smart Chief Inspector-to-be. HANG and KA have dinner together, during which KA says she has overheard his conversation with his mates inside the pub the other day. To please CHU, YEE offers to take her to a famous Chinese medicine practitioner for a check-up……

The police have found some of CHU’s remains, which make them believe that she has been killed already. HANG’s staff have packed up their things and are about to leave POK’s mansion. LAI catches POK weeping inside his bedroom. She feels for POK and tries to console him over the death of CHU. The kidnapper has sent YIN a box of CHU’s belongings. POK discovers that CHU’s watch strap has been engraved with a jumble of strange words, based on the clues in which, he finds a mysterious website and a clip of TING killing a girl in bath. Eager to find out what is going on, POK asks TIN out for a meeting at his laboratory. LAI learns about a strange happening from ON, which makes her believe that POK may have been at risk of harm… POK gets an anonymous SMS revealing CHU’s whereabouts. LAI finally manages to locate CHU and save her life……

POK means to argue with HO on the Web, allowing the police a little more time to trace the suspect’s whereabouts. HANG and the Special Duty Unit manage to locate the hut where HO has been hiding, but an explosion occurs as soon as they step inside. HO has held POK hostage and is resolved to perish with him… LAI goes to visit POK who is lying unconscious in the hospital. She keeps talking to the scholar in a cheerful tone, hoping that this will help awaken him from his coma. HEI has won the Hong Kong Mathematical Olympiad for Primary Schools. When interviewed on TV, the boy gives special thanks to Yaumatei Fresh Fruits Wholesale Market School and speaks of his pride in it. POK asks to get back with LAI but is rejected immediately. Knowing that KA is returning to Singapore, HANG rushes to the hotel to see her. To convince KA of his sincerity, he has even tendered his resignation……