Japan terrorist NAOTAKE's meeting with the East Africa terrorists is not successful and they start a gunfight. Off duty police officer CHONG YAU-KIT discovers it but he stays calm. CHUNG YAT-KA, member of the Hong Kong Anti-Terrorist Force (ATF), learns that the gunfight at the shopping mall is related to the terrorists and she rushes to the place. ATF commander SHUM CHI-NGO asks YAU-KIT to provide information to them. YAU-KIT's mother TONG SUK-FAN is worried after learning about the case. YAU-KIT discovers his elder brother YAU-CHING fighting with others. YAU-CHING has become the gang leader BLACK DOG's subordinate. BLACK DOG receives an order from the East Africa terrorists to kill NAOTAKE and he asks YAU-CHING to carry out the task. When SUK-FAN is working, she is frightened to discover that YAU-CHING is trying to kill NAOTAKE. She stops him and she is sent to the hospital after the shock……

YAU-KIT finds YAU-CHING acting strangely and he tries to capture him but YAU-CHING escapes. On the other hand, the East Africa terrorists and BLACK DOG join hands together to rob the bank. YAU-CHING discovers a bomb inside the travel bag and he throws it into the river immediately. YAU-CHING and the others try to meet up with BLACK DOG. While following them, YAU-KIT is injured and being captured by the East Africa terrorist. The East Africa terrorists use the bank's decoder to perform illegal activities and YAU-CHING informs ATF. YAU-CHING is actually an undercover police of the Serious Crime Unit for monitoring BLACK DOG's activities. The incident is over and the brothers visit SUK-FAN at the hospital. SUK-FAN is relieved to learn about YAU-CHING's real identity. YAU-CHING plans to take leave but CHI-NGO invites him for a meeting. YAU-CHING meets YAT-KA and he is mesmerized by her beauty. CHI-NGO invites YAU-CHING to work for ATF.

YAU-KIT falls in love with YAT-KA at first sight. He learns that ATF is recruiting new members. With the support of ATF supervisor KO WAI and his elder brother YAU-CHING, his application is successful and he will be having a series of training with YAU-CHING in the camp. YAU-CHING is very arrogant for CHI-NGO has invited him to join the team personally. All classmates are dissatisfied. YAT-KA enters the camp to teach them computer hacking techniques. YAU-KIT is very nervous upon seeing her. YAU-CHING is very active and he dates YAT-KA by making use of Trojans. YAU-CHING wants to walk YAT-KA home but he is not successful. However, he discovers that YAT-KA comes from a rich family. When YAT-KA has left, YAU-CHING and YAU-KIT drink together but this is breaking the rules of the campsite. CHI-NGO discovers it and they are very worried for they will be punished...

In order to pursue YAT-KA, YAU-CHING and YAU-KIT are using different tactics. YAU-KIT waits patiently while YAU-CHING takes the initiative to date her. KO WAI learns that they might be expelled from the training camp and he warns YAU-CHING. With the help of the Public Relations Unit, Magazine reporter YIP TING comes to interview them and she gets to know YAU-CHING. In order to please YAT-KA, YAU-KIT decides to make a video with her photos. YAT-KA finds YAU-CHING interesting and she visits him. One of the trainees CHING-NAM has lost his love. YAU-CHING and the others accompany him to go drinking at the pub. In order to help others, YAU-KIT fights with the gangsters and he is arrested by the police. When everybody return, CHI-NGO punishes them and CHING-NAM is kicked out of ATF. YAU-CHING and YAU-KIT decide to negotiate with CHI-NGO.

After the incident, CHI-NGO tries to make the training even harder for them. YAU-CHING and YAU-KIT are trapped inside a freezer. They are then asked to clean the kennel. YAU-CHING feels that CHI-NGO is against him. YAU-KIT accidentally discovers that YAT-KA's ringing tone is the same as his video's background music and he misconceives that YAT-KA is interested in him. However, YAT-KA is actually interested in YAU-CHING. YAU-CHING returns home during holidays and SUK-FAN tries to remonstrate with him. YAU-CHING starts to examine himself. CHI-NGO allows CHING-NAM to return to the campsite. YAU-CHING and YAU-KIT change their perception on CHI-NGO completely. They decide to follow CHI-NGO's orders and they are determined to complete the training. When the team are waiting for their examination results from the ATF, they suddenly receive an order since the hiding place of some terrorists is discovered……

It is CHI-NGO's idea to invite the ATF trainees to join their work for he wants to give them a final test. In order to rescue the hostage, YAU-CHING and YAU-KIT ignore the instructions from their supervisor. After learning that this is actually a test arranged by CHI-NGO, YAU-CHING is very upset. He tries to negotiate with KO WAI and CHI-NGO but it doesn't work. YAU-CHING and YAU-KIT believe that the chance for admission to ATF is very low. All trainees gather at the ATF headquarters to wait for the result. YAU-CHING and YAU-KIT are selected eventually because CHI-NGO appreciates YAU-CHING's ability to make quick decision during critical situations. YAU-KIT is happy for he can work with YAT-KA in the future. YAN-MEI from the Intelligence Unit of ATF discovers that YAU-KIT is interested in YAT-KA and she encourages him. KO WAI overhears their conversation accidentally and he makes a decision.

An important witness in the South Korea terrorists case is being killed and this prevents ATF from carrying out further investigation. YAU-KIT is very upset. YAU-CHING and YAT-KA console him. ATF tries to investigate the immigration record of South Korea and they discover that a famous South Korea terrorist has came to Hong Kong. CHI-NGO believes that the terrorist is planning to kill a South Korea politician during the Korea farmers' protest. He asks YAU-CHING and WANG-LEUNG to follow the terrorist. YAU-CHING believes that YIP TING has contact with the terrorist. YIP TING successfully hides away from others during the transaction and returns to the publishing house. However, she is worried that the ATF will carry out investigation on her.

With the help of YAU-CHING, all the South Korea terrorists are captured by ATF. CHI-NGO is surprised that YAU-CHING has got some insider information of the South Korea terrorists but he did not question him. YAU-CHING meets up with YIP TING secretly. YIP TING provides information to YAU-CHING but she requires YAU-CHING to keep her identity a secret. YIP TING and KIM-HANG start a quarrel for EDMOND has betrayed the organization. KIM-HANG finally apologizes to YIP TING and they reconcile with each other. KIM-HANG decides to support YIP TING's decision to quit her job and study abroad. YAU-KIT insists to join the Intelligence Unit and he carries out investigation for ATF alone. He finally finds some useful information for the Intelligence Unit and he reports it to YAT-KA and CHI-NGO. YAU-CHING knows that YAU-KIT wants to join the Intelligence Unit and he promises to help him.

EDMOND suddenly dies at home and YIP TING helps to provide information to the police. After examining the dead body, it is confirmed that EDMOND has taken too much drugs. LOK-MAN bursts into tears after knowing it. Since EDMOND has died, ATF is not able to continue their investigation on "Scaredy Bird". YAU-CHING tries to question YIP TING since she has visited EDMOND but he finds nothing useful. KIM-HANG is very shocked to learn from YIP TING that EDMOND has died. He suggests YIP TING to study abroad first and he will handle the other matters for the organization. After studying EDMOND's past record, ATF finds the munitions supplier who dealt with EDMOND before and they question him with lie detector but the munitions supplier knows nothing about the "Scaredy Bird". CHI-NGO finally decides to stop the investigation on EDMOND's social network.

LOK-MAN finally admits to YIP TING that she is abusing drugs and she promises to quit it. However, YIP TING doesn't trust LOK-MAN anymore. YIP TING discovers that her laptop computer is attacked by a hacker. After investigation, she discovers that the hacker is staying at LOK-MAN's place. YIP TING finds LOK-MAN even more suspicious. She tries to put eavesdropping device at LOK-MAN's mobile phone and she discovers that LOK-MAN is helping KIM-HANG to monitor her. On the other hand, YAU-CHING brings YAT-KA home and introduces her to SUK-FAN. SUK-FAN is overjoyed to see her future daughter-in-law but YAU-KIT is very upset.

SUK-FAN is attacked by birds and she is sent to the hospital for treatment. KIM-HANG leaves the hospital after recovering from an operation. He wants YIP TING to stay by his side and he lies to her that EDMOND is the one who killed her father. ATF tries to find out if the death of birds is related to biochemical attack and a poison gas factory is discovered. Somebody has stolen poisonous thallium from the research institute of university. The person involved in the case is YAT-KA's old classmate and she goes to the research institute alone for investigation but she is trapped in a fire. ATF assigns staff to visit the thallium expert Professor WONG. Professor WONG is a friend of YIP TING's father and YIP TING visits him to find out the truth behind her father's death. After investigation, ATF discovers that Professor WONG's assistant is involved in the case……

YIP TING visits Professor WONG again but she is being rejected. She meets YAU-CHING instead who is visiting Professor WONG as well. The Hospital Authority reports to ATF that people who were in touch with the birds are poisoned by thallium. YAU-CHING discovers that SUK-FAN is on the list. YIP TING discovers that the Hospital Authority has located all patients suffering from thallium poisoning to the same hospital and she meets YAU-CHING's mother there. In order to hide away from the Scaredy Bird, Professor WONG and his assistant decide to leave Hong Kong but the Scaredy Bird captures Professor WONG's assistant. YIP TING meets Professor WONG again and she helps him to escape. YAU-CHING and WANG-LEUNG wait at the hotel. They finally meet the Scaredy Bird's spy and they start a gunfight. In order to escape, the Scaredy Bird captures YIP TING as a hostage and runs away by car. YAU-CHING follows them by car.

KIM-HANG is very nervous to learn that YIP TING is injured during the gunfight and he rushes to the hospital to visit her. LOK-MAN feels that YIP TING is hiding something away from them but KIM-HANG believes that YIP TING is not suspicious. YIP TING meets Professor WONG secretly and Professor WONG tells her truth behind her father's death. Professor WONG surrenders himself to ATF and he requests for protection. He also provides all the research information of thallium to ATF. With the help of YAT-KA, YAU-CHING finally recovers the data and the doctors develop an antidote successfully. CHI-NGO tries to draw the Scaredy Bird out with a substitute. He suspects that there is a spy in ATF and he asks YAU-CHING to take Professor WONG away secretly. However, CHI-NGO's plan is exposed and the Scaredy Bird sends a group of people to attack the safe house……

KO WAI learns that YAU-CHING is fighting alone and he sends the Operations Unit to the safe house but they fail to find YAU-CHING. CHI-NGO has lost his confidence and everybody in ATF is desperate. YAU-KIT is upset that CHI-NGO has given up searching and he asks his police friends to help searching for YAU-CHING. YAT-KA takes leave to carry out investigation by herself. YIP TING tries to find out KIM-HANG's plan by eavesdropping device. She also follows KIM-HANG and LOK-MAN secretly. ATF finally finds clues of YAU-CHING's whereabouts and YAN-MEI informs YAT-KA secretly. YIP TING meets KIM-KANG while carrying out investigation. KIM-HANG worries that she will be discovered by the spy of Scaredy Bird and he kicks her away. YIP TING therefore has a chance to inform ATF so that they could stop the Scaredy Bird's plan. The spy of Scaredy Bird contacts ATF by video conferencing and they show them the scene of YAU-CHING being killed……

YAU-CHING has died and everybody in ATF is depressed. YAU-KIT tells SUK-FAN the truth but SUK-FAN cannot accept it. CHI-NGO is suspended from his duty and KO WAI is in charge of the Intelligence Unit instead. KO WAI asks the team to stop following YAU-CHING's case but he asks some outstanding ATF members to continue investigating YAU-CHING's case secretly. YIP TING is very shocked with YAU-CHING's death. However, she later reveals to KIM-HANG that she wants to work for the Scaredy Bird. YAU-KIT discovers from YAU-CHING's belongings that he used to date with YAT-KA in a certain location. He goes there and discovers YAT-KA is staying there alone. LOK-MAN asks the spy of Scaredy Bird to hide in the urban district instead. YAU-KIT and CHING-NAM discover the spy during investigation. CHING-NAM's identity is exposed and he is injured by a gun. Operations Unit of ATF arrives to surround the place...

Since YAU-CHING has died, YAU-KIT wants to take his place in the Investigation Unit of ATF but KO WAI rejects his request. YAU-KIT, SUK-FAN and YAN-MEI visit YAT-KA together. They discover that YAT-KA wants to leave Hong Kong after losing her love. YIP TING installs a CCTV at KIM-HANG's office secretly and she discovers a secret room there. YAU-KIT worries that the Scaredy Bird will kill the injured terrorist. He seeks help from YAN-MEI and arrests the suspicious person successfully. KO WAI finally approves YAU-KIT's application to join the Investigation Unit. YAT-KA discovers the video prepared by YAU-KIT long time ago and she is deeply touched. YAU-KIT decides to take care of YAT-KA for YAU-CHING...

YAU-CHING wakes up to discover that he is staying in a remote hospital in China. YIP TING receives a secret letter from Professor WONG. Based on the information given by Professor WONG, YIP TING discovers that CHI-NGO is meeting somebody from the Scaredy Bird secretly. YAU-KIT invites YAT-KA to eat with him and SUK-FAN. YAT-KA meets LAI-HIM there and she treats him coldly. YAU-KIT declares his love to YAT-KA. With the help of YIP TING, YAU-CHING returns to Hong Kong illegally to carry out investigation on the case. LOK-MAN learns from the ATF spy that YAU-CHING is still alive and KIM-HANG is very shocked. CHI-NGO passes through internal investigation successfully and he returns to work as a commander at ATF. CHI-NGO learns that YAU-CHING is alive and he wants to carry out an internal investigation on him. YAU-KIT is dissatisfied.

YAU-CHING wonders why Scaredy Bird knows the whereabouts of the safe house and he questions CHI-NGO. CHI-NGO admits that he has made a mistake but he is not giving any explanation. YAU-CHING tidies up the letters at home and he discovers that YAU-KIT has sent YAT-KA presents. YAU-KIT discovers that YAU-CHING has lied to ATF and he reports it to KO WAI. CHI-NGO decides to carry out investigation on YAU-CHING. In order to urge YAU-CHING to tell the truth, CHI-NGO tortures him. YAU-KIT asks him to reveal the truth as well but YAU-CHING scolds him for wanting to pursue YAT-KA. SUK-FAN visits YAU-CHING at the headquarters and YAU-CHING gives her a note secretly. SUK-FAN meets up with YIP TING and LOK-MAN discovers it. When KIM-HANG is trying to kill YIP TING, he suddenly stops and forces LOK-MAN to hide the secret from their organization so that they could save YIP TING.

YAT-KA helps YAU-CHING to hide away from ATF members and to steal information from the data bank so as to prove that CHI-NGO has committed crime. However, CHI-NGO suddenly arrives at the data bank as well. CHI-NGO tells YAU-CHING that the Commissioner of Police has issued a secret order. Since there is a spy in ATF, he wants YAU-CHING to be an undercover police by working for the Scaredy Bird. YAT-KA has helped YAU-CHING to escape and she is suspended from her work. YAU-KIT is very dissatisfied with CHI-NGO. YIP TING's good friend doesn't want to be involved in the fight with the Scaredy Bird and he decides to hide away in another country. After sending him away by car, YIP TING suddenly collapses. YAU-CHING goes home to say goodbye to SUK-FAN secretly. YAU-KIT follows him and discovers that he is acting intimately with YIP TING. YAU-KIT tells YAT-KA and YAT-KA is deeply disappointed……

CHI-NGO and the other ATF members go to the hospital to safeguard the Scaredy Bird member since he has just woken up. YAU-KIT discovers that WANG-LEUNG is sending message secretly. The spy tries to kill the suspect but YAU-KIT stops it. CHI-NGO asks YAU-KIT and YAN-MEI to join the investigation team secretly. YAU-KIT discovers that CHI-NGO has been working hard on the case secretly and he appreciates it very much. Besides arranging a spy at ATF, LOK-MAN tries to get close to WANG-LEUNG as well and they become lovers. With the help of YIP TING, YAU-CHING meets up with KIM-HANG and reveals that he wants to join the Scaredy Bird. KIM-HANG requests YAU-CHING to put a bomb at ATF as a way to prove his loyalty. With the help of LOK-MAN, YAU-CHING sneaks into ATF but YAU-KIT discovers him. During the time, YAT-KA sneaks into the data bank as well for she wants to steal CHI-NGO's secret data……

YAU-CHING puts a bomb at ATF headquarters. When he runs away, YAU-KIT stops him by pointing a gun towards him. YAU-CHING has no choice but to shot YAU-KIT. When everybody returns, they discover that CHI-NGO is seriously injured by the explosion. YAT-KA visits YAU-KIT at the hospital. YAU-KIT is concerned about SUK-FAN's feelings and he did not tell her that YAU-CHING has shot him. However, SUK-FAN overhears his conversation with YAT-KA. YIP TING agrees to bring SUK-FAN to YAU-CHING. ATF people try to look for WANG-LEUNG but they fail. LOK-MAN has brought WANG-LEUNG to Scaredy Bird's lab already. YAT-KA is not getting along well with her father LAI-HIM but she suddenly attends his press conference for she wants to talk to LAI-HIM alone. LAI-HIM learns that YAT-KA is upset for YAU-CHING is missing and he decides to meet up with YAU-CHING. YAU-CHING is shocked to learn about LAI-HIM's real identity.

YIP TING asks YAU-CHING to tell her who is the leader of Scaredy Bird but YAU-CHING only tells her the things about LAI-HIM. YIP TING meets YAT-KA and YAT-KA tells her everything she knows. YIP TING also tells YAT-KA that she was pretending to YAU-CHING's lover and they reconcile with each other. After investigation, ATF believes that WANG-LEUNG is trapped in one of the drug factories owned by LAI-HIM. YAU-KIT and his colleagues go to the drug factories to carry out investigation. WANG-LEUNG wakes up and he wants to escape. YAT-KA resigns from her job in ATF and she returns to work in LAI-HIM's company. YAU-KIT misses her. KIM-HANG is very stressful. He has got a heart attack and is sent to the hospital. He asks YIP TING to look for the testament after his death. KIM-HANG leaves the hospital and he resigns from his work at the Scaredy Bird. YAU-KIT finds YIP TING suspicious and he goes to the publishing office to question KIM-HANG……

YIP TING recalls that KIM-HANG asked her to take something important at home before his death. She returns home and discovers that the place has been ransacked already. Luckily, the Scaredy Bird member list that KIM-HANG left for her is still there. When YIP TING leaves, she meets LOK-MAN and they start a fight. CHI-NGO asks YAU-CHING to look for YIP TING and YAU-CHING brings YIP TING to YAT-KA's place. YAU-KIT discovers that KIM-HANG and LAI-HIM are in touch. He therefore carries out investigation on LAI-HIM. He discovers that YAT-KA is not at work and he visits her. YIP TING suddenly visits LAI-HIM. She hands over the Scaredy Bird member list to LAI-HIM in exchange for her freedom. In order to protect all colleagues in Smart Magazine, YIP TING decides to shut down the publishing house. The Scaredy Bird assigns the first task to YAU-CHING and YIP TING. They are requested to follow a young girl.

YAU-CHING tells YAT-KA that he has found WANG-LEUNG. In order to find the truth, YAT-KA tries to get information from DR.KING. YAU-KIT follows DR.KING and he discovers that WANG-LEUNG is trapped for trying their medicine. YAU-KIT tries to save WANG-LEUNG but CHI-NGO suddenly arrives to stop him. YAU-KIT finally knows why YAU-CHING has betrayed ATF and he decides to support his work. YAT-KA hopes that YAU-CHING could leave Scaredy Bird and run away with her. However, YAU-CHING continues to help LAI-HIM and he kidnaps the young girl with YIP TING. YAT-KA discovers LAI-HIM's plan and she tries to stop it. LAI-HIM is enraged and he traps her in the drug factory. YAU-KIT carries out investigation on the young girl's family and he discovers that her father is a famous professor in virology. LAI-HIM threatens him to help with their research.

In order to save his daughter's life, the professor decides to help LAI-HIM in developing his biochemical weapon. After developing the biochemical weapon and the antidote, LAI-HIM decides to carry out his plan. He invites YAU-CHING and YIP TING to join him as well. YAT-KA escapes from the room by making use of her expertise and she discovers the biochemical weapon's data file in LAI-HIM's computer. CHI-NGO returns to ATF to lead the team in fighting against the Scaredy Bird. The terrorists sneak into the shopping mall. YIP TING and YAU-CHING are involved in it as well. They are asked to put two time bombs inside the shopping mall's ventilation system respectively. YAU-CHING subdues the terrorists successfully and CHI-NGO's people arrive at the shopping mall to help him. The terrorists bring YIP TING to the rooftop and hang her with the time bomb……