LAM TING-TING gets injured while trying to save an old lady, in the course of which she happens to discover a dreadful murder of four members of the same family. Senior Chemist of the Forensic Science Division KO YIN-POK arrives at the scene. From the bloodstains on the ground he infers that there is still at least a survivor. TING admires him so much for his intelligence and extraordinary powers of observation. Senior Inspector LEUNG SIU-YAU, who has been newly transferred to the Regional Crime Unit, believes that the murderer was aiming for the diamonds kept in the house owner TAM TAK’s safe. POK tries to catch up with the garbage truck to look for the murder weapon. YAU checks out the registration number of the truck and informs POK immediately. POK finally manages to find a knife and some other evidence in the refuse dump. YAU follows Forensic Pathologist KOO CHAK-SUM to the mortuary for the autopsy.… ...

SUM points out that they have to keep a clear head to make a fair judgment while looking for the murderer, and YAU is finally convinced. TSAU claims that he was involved in a car theft when the murder took place, which is proved to be true after YAU’s investigation. YAU blames the owner of the stolen car for putting up with the thieves again and again. KOO CHAK-YIU, POK’s wife and SUM’s elder sister, was paralyzed in a car crash years ago. POK and SUM are astonished to hear that YIU is suffering from liver cancer. SUM used to be a problem teenager but YIU’s desperate attempt to save him touched him deeply and changed his whole life. SUM feels so sorry for YIU and wonders why fate is so cruel to her. POK cannot do anything but give him a few words of consolation. SUM discovers that the murderer has been hiding something. Immediately he goes and explains to YAU his views and analysis.… ...

YAU takes SING back to the scene for a reconstruction of the murder. As she is questioning SING, POK comes along and recovers the diamonds hidden inside the fish tank. There is strong evidence against SING and he has no choice but to admit what he has done. YAU’s boyfriend is in love with someone else and will be getting married overseas. YAU tries to suppress the pain of being dumped and joins a celebration party with her staff. After the gathering, she goes to a pub for a drink, where she meets SUM. Knowing about her recent break-up with her boyfriend, SUM tries to offer her a few words of comfort. POK is impressed by TING’s excellent observation skills and decides to offer her the job. Someone is killed by a brick thrown from a height. TING follows POK to the scene for an investigation.… ...

POK is very rude to TUNG, which shocks everyone around to the core. TUNG has bought YIU some herbal products but POK does not seem very grateful at all. Having noticed the problem between them, SUM goes to have a talk with POK. YIU and POK run into a long-lost friend Dr. LAM PUI-PUI at the hospital, who has recently returned from the States. A rush of mixed feelings come over them when they get face-to-face again after all these years. PUI and POK used to be an item. POK tells PUI that he knows from the very start that TING is her sister. WOON discovers from SUM a questionable point in the child abuse case. The mother finally admits abusing her daughter CHAN SHAN-SHAN. SUM tries to save a problem teenage girl CHIU SUET-MAN but is alleged to have sexually harassed her. Fortunately YAU believes SUM and he can therefore stay away from trouble.… ...

YAU comes along to arrest BLACK YIU. BLACK YIU pushes TUNG, who happens to pass by, down to the ground while escaping but is captured eventually. TUNG is required to have a medical examination, during which he is diagnosed with cataract. YAU and SUM offer to send TUNG home. YAU points out that POK is not a dutiful son. SUM tells YAU about his past and reveals that the reason he participates in voluntary youth work is that he wants to fulfill YIU’s wish and dream. YIU urges POK to go and watch the drama performance with PUI on her behalf. POK points out that there is insufficient evidence to charge BLACK YIU. POK and YAU become suspicious of LUI YAU-KUEN who has come to post bail for BLACK YIU. Through close collaboration, POK and YAU finally manage to track down the real culprit. SUM pays TUNG a visit, where he bumps into YAU. The three of them then decide to visit YIU together.… ...