Born KO TAI-HEI, Detective COLUMBO has an IQ of up to 283, and is able to achieve a detection rate as high as 99%. Despite his outstanding credentials, he is labeled as a dangerous and combative figure that needs to be kept under watch. COLUMBO has launched a massive dragnet for three suspected kidnappers of a comprador. Having learnt from his subordinate PAU PING-ON that the crime scene has been brought under control, COLUMBO starts eating and drinking inside a tent. ROBINSON is taken hostage by one of the kidnappers and later gets shot by COLUMBO in the confusion. Fuelled with anger, ON blames COLUMBO for being too unscrupulous with everything he does. During their conversation, ON keeps addressing COLUMBO as “HEI”. Superintendent SCOTT is COLUMBO’s supervisor and has long been a thorn in his flesh……

Flashbacks: LOUIS reveals to HEI how he got to know his father KO NGAU. Now that NGAU has passed away, LOUIS needs ON to help arrange a final meeting for HEI and his late father. With the help of LOUIS, HEI has not only acquired permanent residence in Hong Kong but is also sent to the Police Academy for a series of training sessions. Unfortunately HEI has failed in all subjects and the then Academy Principal SCOTT is going to kick him out of the school soonish. Knowing that HEI will be expelled from the Police Academy for his poor performance, ON notifies LOUIS at once and LOUIS is kind enough to intercede for HEI. ON’s wife and mother are caught in a fire, but they just get rescued by HEI in the nick of time. ON has regarded HEI as a member of his family ever since then……

A senior officer orders LUNG to engage in a fencing duel with EVA, and LUNG manages to defeat the girl in just a few seconds. EVA comes to see LUNG as his supervisor and asks him to follow her instructions in all circumstances. EVA would like to see COLUMBO, but ON comes up instead explaining that COLUMBO is busy dealing with a tough case, which is also the biggest drug case in Hong Kong’s history. As EVA is almost frightened to death by a swarm of cockroaches inside the warehouse, COLUMBO shows up and comes to her rescue. COLUMBO explains to the journalists that the whole operation is led by EVA, which causes EVA to make quite an impression on him. Though becoming more and more annoyed with COLUMBO, ON believes that this man still has a conscience and he is still looking forward to his reunion with the original HEI……

ON is shocked to see COLUMBO break down crying with the china doll in his hand. The headache-stricken COLUMBO asks for an urgent brain operation in order to transform back into his original self. At his request, ON sends COLUMBO to the hospital at once. Fearing that the surgery might go wrong in one way or another, COLUMBO pleads with ON to write a letter to MUI to let her know that the china doll has already been repaired. LOUIS asks ON to look for COLUMBO, but instead of following the instructions, ON hands him a resignation letter on behalf of the renowned detective. In the meantime, LOUIS gets a long-distance call from the Hong Kong Governor who is currently on duty in London. LUNG visits his mother’s grave on the anniversary of her death, during which he takes a vow never to engage in gambling and bribery as his father CHOI TIN did in the past. LUNG is surprised to hear that TIN will be working with him in the same office……

ON is awakened by the baby’s crying in the early morning. With no better alternatives, he decides to bring the baby back to the police station. Manager WONG and his wife are shocked to see their son in the police station. Surprised yet happy, the couple grab back the baby at once. To avoid any possible trouble, ON claims to have found the baby outside the police station. ON finds COLUMBO so annoying that he cannot stand him anymore. COLUMBO shows ON a remittance receipt claiming that he has sent HK$500,000 to his wife in the UK. Not wanting ON to cause him any trouble, COLUMBO urges him to leave Hong Kong as soon as possible. ON takes out the china doll, but to his great surprise, COLUMBO grabs it and throws it onto the floor without a second thought. COLUMBO pretends to be so concerned about EVA’s relationship with LOUIS, as if he is most reluctant to see her argue with her father only for his sake……

COLUMBO manages to attract much attention and praise from EVA. EVA is keen to find out more about the china doll, so COLUMBO starts to spill the beans about his past with MUI. SCOTT asks LUNG to put a listening device inside COLUMBO’s office for eavesdropping purposes, but is rejected. LUNG finally decides to move to TIN’s place, giving COLUMBO a perfect excuse to pay them a visit. While visiting the CHOIs, COLUMBO manages to hide a listening device inside their living room. Curious about how COLUMBO got shot three years ago, EVA asks LUNG to accompany her to the scene for a thorough investigation on his new appointment as a CID Officer. LUNG and EVA enter a shabby hut in the neighborhood, shortly after which a suspicious-looking man suddenly pops up from nowhere. EVA runs out to catch the man but is knocked unconscious during their fight. LUNG tries to resuscitate EVA but is mistakenly thought to be sexually assaulting her……

COLUMBO asks EVA to stop investigating his case, as it would be too dangerous for her. LUNG hears TIN calling for help upon his return home. EVA hopes COLUMBO will find his Miss Right sooner or later, and suggests him join the upcoming Police Banquet so as to widen his social circle. ON’s wife JOANNA shows up in the banquet, and reveals to EVA how COLUMBO risked his life to save her and her mother-in-law a couple of years ago. Not wanting EVA to get cheated, ON is going to reveal the sordid truth behind the hypocritical mask of COLUMBO, but is stopped in the nick of time. COLUMBO forbids ON to say anything against him as ON owes him a huge debt that can never be repaid. ON goes through his old photos and recalls all the happy times he shared with HEI and JOANNA. ON gets into a church and prays to Our Lady asking for the return of the good-natured HEI. He is even prepared to give his life to fulfill his wish for HEI……

JOANNA can tell from EVA’s response that she is in love with COLUMBO. Much excited about EVA’s romance with COLUMBO, JOANNA describes the super detective as a loyal gentleman. But when she suspects ON being a secret admirer of EVA, her mood turns unexpectedly downbeat. LOUIS is shocked to hear that ON and COLUMBO have sustained life-threatening injuries and are both being treated in hospital. Director LI points out to LOUIS that ON and COLUMBO are so severely injured that they have just a slim chance of survival. Desperate to find out what has happened between ON and COLUMBO, EVA offers to lead the investigation into the incident. MUI has kept a huge pile of news clips about COLUMBO and the various cases he has solved. She seems to have deep respect for COLUMBO while bearing a noticeable resentment towards EVA. MUI runs into EVA inside the hospital lift……

EVA confides to COLUMBO’s body, during which the heart machine is found to be working again. Shocked yet happy, EVA rushes out to look for the doctor at once. EVA notices a kiss mark on COLUMBO’s face. Curious about who has come to see COLUMBO, EVA goes out to have a look, and finally manages to locate MUI down the stairway. EVA tries to seek LOUIS’ permission to transplant COLUMBO’s brain cells into ON’s body. JOANNA is so desperate to save ON that she even goes down on her knees and pleads with LOUIS. Touched by her persistence, LOUIS finally gives in and agrees to her request. Now that his condition is becoming stable, ON is placed in the same ward with COLUMBO. COLUMBO has been in a coma for a month, during which thefts have become increasingly rampant across the city. LOUIS needs SCOTT to rectify the situation as soon as possible, and SCOTT too starts putting pressure on EVA. JOANNA decides to go back to England……

EVA confides to COLUMBO’s body, during which the heart machine is found to be working again. Shocked yet happy, EVA rushes out to look for the doctor at once. EVA notices a kiss mark on COLUMBO’s face. Curious about who has come to see COLUMBO, EVA goes out to have a look, and finally manages to locate MUI down the stairway. EVA tries to seek LOUIS’ permission to transplant COLUMBO’s brain cells into ON’s body. JOANNA is so desperate to save ON that she even goes down on her knees and pleads with LOUIS. Touched by her persistence, LOUIS finally gives in and agrees to her request. Now that his condition is becoming stable, ON is placed in the same ward with COLUMBO. COLUMBO has been in a coma for a month, during which thefts have become increasingly rampant across the city. LOUIS needs SCOTT to rectify the situation as soon as possible, and SCOTT too starts putting pressure on EVA. JOANNA decides to go back to England……

SCOTT claims to have caught the perpetrator of the acid attack, but EVA believes that the so-called suspect SHE PING is just a scapegoat for the real culprit. EVA receives a letter from JOANNA stating that she is not coming back to Hong Kong and asking EVA to look after ON. LOUIS needs LUNG to have a jog with him, during which he encourages the lad to woo EVA. MUI reads in the newspapers that COLUMBO has woken up from coma. Later she arrives at the police station with a big bowl of soup, and introduces herself as the wife of COLUMBO. TIN brings MUI to EVA’s office. Knowing that MUI used to have an intimate relationship with COLUMBO, EVA shows open hostility to her. The two ladies begin to run out of conversation after a bitter quarrel. A woman is reportedly trying to jump off a building to kill herself, so LUNG and EVA hurry to the scene to have a look……

TIN points out that LUNG and EVA are worlds apart in family background and social status, and suggests the lad go out with HAN instead. As arranged by LUNG, the real estate broker who is responsible for the transaction between MING and MUI has come to the police station to give a statement. Having studied the real estate broker’s statement carefully, EVA believes that MUI must have something to do with MING’s disappearance. As soon as she opens the door, the messy-haired MUI is shocked to see EVA waiting outside her apartment. EVA asks MUI a series of questions, following which she urges LUNG to search her place, but is rejected. In response to EVA’s endless questioning, MUI reluctantly reveals how she was forced to become a prostitute when she was younger. Feeling insulted and humiliated, MUI starts weeping. Knowing that COLUMBO has mysteriously disappeared, LOUIS and EVA rush to the hospital to see what is going on……

EVA accompanies COLUMBO back to his place, during which she plucks up the courage to confide in him. Sadly COLUMBO is totally clueless as to what she is talking about. Believing that the china doll may help bring back his memories, EVA decides to give it a try and takes COLUMBO into his own bedroom. Without any identity documents with her, MUI remains in a coma after the car crash. LOUIS suggests sending COLUMBO back to the hospital at once, but EVA insists on keeping him at home as this will make recovery so much easier. She herself is going to stay with COLUMBO so that she can look after him in a home environment. LUNG offers to help EVA, and the pair get on really well with COLUMBO. The three of them are so close that they even go jogging together. Director LI points out that COLUMBO is recovering well and is fit enough to undergo a medical assessment……

EVA and LUNG go to see PING in the detention center, during which they manage to make him reveal the truth by stratagem. LUNG infers that MING was so eager to sell the flat and leave Hong Kong that he ended up falling into MUI’s trap. MUI is therefore regarded as a prime suspect. TIN asks HAN how she is getting on with LUNG, and HAN replies that LUNG has already found his Miss Right. COLUMBO has got his memories back, but is shocked to the core when he sees ON lying unconscious in bed. He keeps shouting ON’s name and finally manages to wake him up. As explained by Director LI, ON’s IQ has mysteriously doubled following the transplantation of brain cells. Knowing that JOANNA has left Hong Kong, ON appears so devastated and vows to change his ways to become a brand new man. LOUIS tells EVA about all the sudden personality changes in ON. To him, ON and COLUMBO are nothing more than monsters……

Not wanting to further agitate the lady, LUNG tries to dig up information from Mrs TONG bit by bit. EVA, on the other hand, is straightforward enough to point out that MING has committed adultery, which comes as a huge blow to Mrs TONG. Mrs TONG is so devastated by the news that she is going to kill herself again. EVA moves back with LOUIS, and even offers to make breakfast for him. LOUIS is so impressed by what EVA has prepared, but EVA just humbly dedicates the honor to LUNG who offers to teach her how to cook. Knowing that LUNG has already located MUI, EVA rushes out to join him in the investigation. HEI has a dream about MUI. After waking up from the dream, HEI discovers ON looking for his wedding ring inside the toilet. ON goes to see Director LI trying to find out more about COLUMBO. HEI manages to find ON’s wedding ring in the toilet but gets beaten up by ON for this soon afterwards……

MUI recalls the past and begins to reveal why she had to purchase the flat from MING. Flashbacks: MING calls the asylum asking its staff to go catch MUI. Just then MUI comes up and starts to tangle with MING. EVA does not believe MUI, so MUI shows EVA the scar she got on her face after the car crash. LUNG would like to meet CHAN KWO for a further probe, but EVA points out that KWO may have been colluding with MUI. EVA is resolved to prosecute MUI for illegally imprisoning COLUMBO, even if she turns out to be innocent of MING’s disappearance. Nurse KAR discovers the severely injured COLUMBO, and EVA is going to find out from ON what has happened. Later EVA finds ON’s wedding ring on the staircase and discovers ON sitting alone on the rooftop. EVA asks ON if COLUMBO has ever been in love with her, so ON points out the truth by revealing how COLUMBO has lured her into his trap step by step……

LUNG updates EVA on the investigation progress in relation to MING’s disappearance, from which he can conclude that MUI has been telling the truth. EVA decides to have a word with Manager WONG about the embezzlement case, from which she wants to find out whether COLUMBO has really done what ON has claimed. After breaking away from LUNG, EVA phones LOUIS at home offering him an apology and revealing her plan to return to England. COLUMBO wakes up from coma and manages to save Nurse KAR who has been held hostage by ON. COLUMBO follows ON to the rooftop to stop him from committing suicide. Soon afterwards the two of them get into a fight and fall off the building together in the confusion. The police have found EVA’s car at the pier, but LUNG believes that she is safe at the moment and has no intention of killing herself. LUNG cannot find ON and COLUMBO in the hospital, but gets the diary of EVA from a nurse later on……

LOUIS suggests EVA take a break by going on an overseas trip, and EVA makes it very clear that she will not be marrying COLUMBO no matter what. EVA is surprised to hear that Director LI and Nurse KAR have both resigned. She goes to see Director LI, who then reveals that COLUMBO has already recovered his memory and been discharged from hospital with ON right away. EVA rushes to COLUMBO’s residence to look for him. COLUMBO offers EVA a sincere apology and states that he is willing to compensate her with his own life. EVA finds a letter from COLUMBO, in which he mentions that he has become a deadly monster. Knowing that MUI has suffered a lot over the decades, COLUMBO feels so sorry for her and decides to look after her for the rest of her life. Just at the same time, COLUMBO discovers that he has got another superpower, which really takes him by surprise……

COLUMBO and MUI get married at the Marriage Registry, and go take wedding photos at a studio after the ceremony. EVA and LUNG go to MUI’s residence to conduct a thorough search, during which EVA reveals how she encountered LUNG on Cheung Chau in her early childhood. Prof LEUNG points out that COLUMBO has taken MUI out of the asylum earlier on in the morning, so EVA believes that the couple will be leaving Hong Kong very soon. ON manages to catch COLUMBO, during which he reveals that SCOTT and his subordinates are already making their way to the plane for the arrest of MUI. EVA tries to wake up the sleeping MUI, but SCOTT appears all of a sudden and claims to be directly in charge of MUI’s case. SCOTT pushes EVA aside and orders his subordinates to arrest MUI. As arranged by ON, a large mob of reporters are gathering at the airport, and ON means to refer to MUI as the suspect of the murder of MING in front of the press……

LOUIS explains that SCOTT has revealed the secret of ON and COLUMBO to the Governor, who then decides to have LOUIS and COLUMBO replaced by SCOTT and ON. LUNG asks for a transfer to work directly under the supervision of SCOTT, for which he is highly praised. EVA goes to the landfill site to look for LUNG. LUNG says he is so reluctant to recall how he got rejected by EVA that he has finally decided to apply for the transfer. EVA asks Prof LEUNG if MUI can be treated in the asylum. Prof LEUNG agrees to her request and promises to do the follow-up for her. But out of the blue, MUI gets taken away by a fake asylum worker. EVA tells LUNG about MUI’s mysterious disappearance, as well as her plan to return to the UK with LOUIS. She asks LUNG to help COLUMBO in his fight against ON and SCOTT, but is rejected……

LUNG’s colleagues have all teamed up against him, but ON gives them a good telling-off for this and admonishes them to collaborate with LUNG in all circumstances. SCOTT is shocked to hear that all the staff in the police station are suffering from diarrhea, but no one is allowed to seek treatment in hospital as ordered by ON. COLUMBO manages to escape from prison, making the rest of the police officers believe that LUNG is just working undercover to spy on SCOTT. ON tries to threaten his colleagues with the news that SCOTT has already moved TIN to the border regiment. But this does not seem to have shaken his colleagues at all and they just make their transfer requests on the spot one after another. SCOTT is promoted to the rank of Chief Superintendent. During the press conference, ON announces that COLUMBO, who is found to be innocent of the murder of MING after the police’s thorough investigation, has already been released……

ON arrives at the airport, but cannot find JOANNA. Later the airline staff reveals to him that JOANNA has had an acute heart attack and been sent to hospital for urgent care. ON blames COLUMBO for causing the deaths of JOANNA and their unborn son. He is so worked up that he is going to kill COLUMBO to vent his anger. But just seconds later, he changes his mind and decides that the best kind of revenge is to let COLUMBO see how he is going to torture MUI. EVA and LOUIS lead a happy and peaceful life in England. EVA learns about the death of JOANNA from LUNG, shortly after which LOUIS is also found to have passed away in his sleep. MUI is sentenced to capital punishment after being convicted of killing MING. LUNG finally manages to locate COLUMBO inside the church the day before MUI’s execution. HEI comes up to see MUI just an hour before the hanging, which gives her a real thrill……

SCOTT is rumored to be the successor to the existing Commissioner of Police who will be retiring soon. ON takes advantage of his identity as a Senior Inspector, and gets more and more heavily involved in corruption. ON seems to have seen the ghost of MUI in the middle of the night, and becomes so frightened that he has fired his pistol several times in the street. This incident is covered in various newspapers the following day, making ON an object of ridicule among his colleagues. EVA meets an Indian who looks so much like COLUMBO on her return flight to Hong Kong. ON and his subordinates arrive at the restaurant to arrest LUNG and HAN who are having their wedding banquet. ON heads for the bride’s room to arrest HAN, but sees nobody inside except for the ghost of MUI……

COLUMBO mistakes NAM for MUI, and starts to confide in her. COLUMBO points out to SCOTT that he will not be prosecuted that he agrees to present the evidence against ON, as guaranteed by the Secretary for Security. COLUMBO returns home and discovers a note left by EVA, in which she mentions that she will be returning to England soonish. ON sneaks into SCOTT’s bedroom, so SCOTT reveals to him how COLUMBO is going to fight back against them. LUNG discovers that ON has booked a flight to London which is scheduled for departure at 3 pm. COLUMBO cracks the safe with his pistol and takes out the accounting records from it. He asks LUNG to apply for a warrant with the accounting records while he himself will hurry to the airport to intercept ON. EVA is shocked to see ON on the plane. To make the plane return to Hong Kong, she pretends to be having a sudden heart attack. ON has hijacked the plane by taking EVA hostage……

KIU comes to tell COLUMBO that KEUNG is still awaiting NAM, making LUNG believe that NAM may have been caught by ON. COLUMBO receives a call from ON, and later promises to get him a boat for his escape to Taiwan. ON is driving to the pier but NAM tries to escape along the way and starts tangling with him. ON loses control of the car and finally crashes into a tree. ON becomes paralyzed as a result of the neck injury, although his speech is not affected. EVA has been in a coma for two months, and her health is deteriorating day by day. According to the doctor, whether EVA can recover will very much depend on her willpower and determination. Having delved into EVA’s subconscious, COLUMBO decides to turn to Prof LEUNG for help. Prof LEUNG explains that COLUMBO will have to fall unconscious before he can connect his mind with EVA’s, but chances are that both of them might never wake up……