Kan Yiu-yeung, Ku Ka-keung, Kiu Po-po and Kiu Tai-nam were once CTRU’s Formidable Quartet. An incorrect decision in an operation caused the breakup of their friendship. And the quartet went their separate ways. Fast-forward to the present and an indiscriminate homicide again brings the quartet together. But there are still certain unresolved issues between themselves. POTT is Counter Terrorism Intelligence Cadre’s other elite task force. Team leader Fong Kwok-hei admires Po-po and asks her to become her subordinate. Team member To Siu-jie fancies her partner Yiu-yeung and finds out Po-po is Yiu-yeung’s ex-lover, so she “starts a war”. Successive explosions happen in the city. While investigating, Po-po asks prisoner-cum-hard criminal Dr. Hong’s for help, and the process is surprisingly easy. Actually, Dr. Hong has some trick up his sleeve.
Yeung Yut Ching, an elite in the bodyguard world, is good at risk management and is the winning team in life. However, his unhappy childhood made him refuse marriage, and fate made him meet Yau Tze Ching, a clever woman who keeps breaking the rules of his life.
Online media editor Ho Ka Yan is ordered to approach the athletics club to find some dirt on them. It's there that she becomes acquainted with running coach Yuen Lik. Due to past regrets, Yuen Lik avoids forming personal relationships with others but gradually grows closer to Ho Ka Yan because of their interactions. Kwok Wong Po's daughter Kwok Pui Yee has taken the initiative to join the club for her own reasons while her dad comes to sponsor the club. Yuen Lik's good friend Lai Shun Fan has entrusted his son to Yuen Lik. It is also revealed that Shun Fan and Ka Yan have a past. At a time when Shun Fan is on the verge of giving up due to his illness, Yuen Lik becomes determined to help his friend get back on his feet. At the same time, Yuen Lik reexamines his life as he decides to step onto the running track once more.
“Summit” was a reputable vehicular stunt team in the film industry, but an accident that happened two years ago made team leader Chai Tai-Chi disband the team. To pass on her late father’s legacy, Sheung Mei-Chu works as a stunt double at film studios while actively seeking to bring the team back together.
After his girlfriend died in a car crash, sorrowful psychologist Chung Tai Yin spends five years investigating the truth of the incident. His girlfriend once conducted a psychological assessment for a schoolyard murderer. Her report indicated that he lacked a motive or violent tenancies. During the course of his investigation, Chung Tai Yin meets Tung Yat, a genius with Asperger syndrome, and his sister Tung Yuet, whom he is mutually dependent with. Tung Yat's lack of social skills gives Tung Yuet a lot of trouble. Many years ago, it even caused police officer Wu Tin Yeung's undercover mission to fail. But because of Chung Tai Yin, they eventually become friends and help Chung Tai Yin with finding the true killer. Wong Hoi Ching, a witness in the case who could not be contacted for many years, suddenly appears and visits the murderer in prison, causing drastic changes in the case.
After the deaths of his first and second wife, cosmetic mogul Cheuk Kwan-Lam, known as "King", tries to turn over a new leaf. As fate would have it, he encounters a resourceful young man known as Ringo Poon, through whom he sees a younger version of himself. The young man also wins the favor of King's secretary Rachel Chan, who believes that Ringo would lead the company, Endless Beauty, to success. Little do they know that Ringo is actually secretly conspiring with a team of talented people on the sly to steal trade secrets from large corporations for money. Ringo has been planning this for years, seeking the best opportunity to take destructive revenge on Endless Beauty.
Hong Kong traffic E&C inspector To Cheuk Fung is dedicated to his mission. He and his subordinates often go undercover so they can easily prosecute those who speed, drunk drive, and hold illegal licenses. Cheuk Fung is an extremely cold person, serious in speech and manner, but he is strangely close friends with the boisterous Sze Ma of the investigation team. The duo are left speechless when they meet the rookie cop Bui Sam Yau, who they assumed would not be able to withstand Cheuk Fung’s strict demands. But after Sam Yau helps Cheuk Fung dispel a worry that he has kept locked in his heart for many years, the two grow extremely close, forming a pseudo father-daughter relationship. Sam Yau’s satisfactory performance catches the attention of Sze Ma, who convinces her to join his team. Sze Ma has been less than pleased with his subordinate Yiu Yiu, who prefers to do everything by the book and fails to catch up to Sze Ma’s painstaking style of investigating. Meanwhile, a racing gang has been wreaking havoc in the streets, sending out provoking messages to the police. Cheuk Fung and his team are given the light to track them down, but he ends up stepping into a dangerous boundary. A dark haze he has been avoiding once again appears before his eyes.