A bomb explodes in a country club where foreign delegates and ministers are meeting. The police receive a mysterious call that a bomb has been planted at a bus interchange. The bomb explodes in the middle of the night. Are the two related? Special Investigations Section officer Chong Yee Tat investigates.
The Police receive a live transmission of a masked hostage tied up beside a bomb-like device. The video taunts the Police to find the hostage within 24 hours.
The Police manage to discover the perpetrator; an adolescent who planned the series of bombings. Yee Tat feels that the public has taken the safety and peace in our country for granted.
Two bodies are found in Orchard Road and in a forested area. They both belong to Indonesian maids, and both suffer strangulation rules. The police finds out that one victim's boyfriend is escaping by boat, and a pursuit ensues on the water.
Coastal Patrol Craft Commander Cheng Ling arrests Matius with the help of the STAR team. Yee Tat recalls a dismemberment case from before, where a victim suffers due to his carelessness. Matius' refusal to plead guilty pushing him to lecture Matius.
Car bombs go off in succession, and recently widowed Qihua becomes a suspect. His wife had committed suicide after learning of his infidelity. Depressed and in debt, Qihua is fired from work and hides from his debtors. Yew Jia questions his son Yongjian, and finds that he seems to be hiding something.
Qihua is proven innocent. His neighbor Yu Tianbao turns out to be the real arsonist. It is revealed that his grandson died from a hit-and-run accident a year ago. Tianbao set fire to the same model of cars that ran over his grandson.
Cheng Ling joins the Special Investigations Section and works under Yee Tat. She encounters a gun murder case on the first day, where the victim Yongtai's house was burgled clean. His wife reveals that 10 years ago, Yongtai brought home a large sum of money. Someone had asked him for a loan the day before his death, but was rejected. Cheng Ling suspects revenge.
One of the burglars Wu Gong is arrested, and pushes all the blame to his accomplice Tou Feng. He claims that Tou Feng's attempts to fund a business was rejected by Yongtai, and decided to kidnap him for ransom. They later got into a fight, and Tou Feng killed Yongtai in a fit of anger before robbing his house.
Tou Feng dies in a shoot out with the police, but Cheng Ling notices that Tou Feng is left-handed, with a misshapen right hand. The murderer of Yongtai is a right-hander. Wu Gong turns out to be the killer. In another case, a girl reports being molested by a police officer, and indecent photographs were taken. The Special Investigations Section begins investigations.
Jinliang admits to receiving free sexual favours from Zhang Yao in exchange for setting her free. He was frustrated after breaking up with his girlfriend Meiqi, and accepted the bribe in a moment of folly. After multiple rejections from Meiqi, he sought Zhang Yao again, and was ultimately arrested.
Two cases of girls being abused by police officers were discovered consecutively. Their nude pictures were made public on the web. One girl, Liting, attempts suicide. From the pictures on the web, Xinyi discovers that the girls share the same characteristics, and suspects the cases are linked. Upon questioning, Liting reveals that she knows the suspect.
Architect Tiansheng is murdered. Before his death, he was separated from his wife and was fighting for the custody of his 7-year old daughter. Yida discovers that Tiansheng had appointed his daughter as the beneficiary of a large insurance payout. If his wife had become the custodian, she would receive the payout. Yida suspects a motive.
A woman Lixuan is murdered the same way as Tiansheng. Her boyfriend Zhiming had never met Tiansheng, nor have Xinhui met Lixuan. The cases appear to be unconnected, but Xinyi suspects a link. Yida and his team finds a visually-impaired man with clues based on an ez-link card.
Weizhong is shot dead by Guixiang, and Wenxiong dies in the line of duty. The police discovers that Xinhui had financial problems, and seduced Weizhong into killing Tiansheng in order to become her daughter's custodian. Zhiming uncovers the ruse, and threatens Xinhui to help kill his girlfriend after their relationship turns sour.
Xinyi deals with three cases of suicide consecutively, and feels for these victims who chose death over life. Yaojia feels that suicide is an act of cowardice. Xinyi recalls the concern Yaojia displayed towards her, and is grateful.
Xinyi's grandfather is robbed, but is rescued by the office thief Ah Qiang. Patrolling officers Guixiang and Guohuang give chase, but Ah Qiang scrambles to get away. When Guixiang wrestles with the actual robber, he recalls Wenxiong's death. The robber manages to get away when Guixiang hesitates.
Yaocheng is on a date at a hotel, and sees Yaojia coming in for an investigation. Yaojia discovers that Chen Donglai is a technician with the hotel maintenance team, and tries to arrest him. He is ambushed by Donglai's accomplices. Yaocheng rescues Yaojia, and the brothers mend their fences.
Xinyi is abducted when she investigates a kidnapping. Yaojia is worried after hearing Situ Yan's view that Xinyi is being held hostage. The kidnappers plot to kidnap Lian Shi En's daughter during the World Security Summit. The police arrive in time and shoot the perpetrator dead. Mastermind Zhengyuan tells Xinyi that he will initiate Plan B.
Zhenyuan negotiate with the police for Lian Shi En, threatening to kill Xinyi. Yaojia replays the footage, and realises that Xinyi is trying to send a message. He attempts to figure out her location, but to no avail. Cenling points out that Xinyi could be referring to another place, and the various divisions sets off. With the clock ticking, will the police be able to find Xinyi and negotiate the crisis?