Heeding a prophecy, a warlord trains two orphans after killing their parents. But the skills he teaches could lead to his downfall.

Kung and Kin's rivalry goes way back to the seventies when they fought over the same girl, who eventually became Kung's wife. Now they run competing phone stores right across from each other on Mongkok's busiest street, and stretch their minds trying to outdo each other with crazy promotions.

Laughing is formally a police undercover. However due to a drug trafficking case, Inspector Pan is hot on his trails. Before Laughing becomes a police undercover, he works under triad leader Yi. Yi treats Laughing as his own brother, however to protect his territory and illegal businesses, Yi instructed Laughing to join the police force and act as his undercover. Laughing is a high-flyer in the police academy. However he never got a chance to join the force because he is specially picked by Inspector Xian to be an undercover in the underworld syndicate. Hence Laughing becomes a “double-undercover”. Yi is happy that Laughing is allocated to the triad of his rival. To make his situation worse, Laughing falls in love with the triad leader’s sister, Karen. Justice, brotherhood and love, what will Laughing decide on? His decision will be a turning point in his life.

Follows an investigator as he prevents a terrorist attack during a symposium held by Hong Kong's Independent Commission Against Corruption. He later finds it has links to human trafficking in Thailand.

Chicken is back in exile. Hung Hing, a triad, is trying to ally with Chicken's new group, the Taiwanese triad San Luen. A contest is on in Hong Kong. The winner will head the Causeway Bay branch.

It tells the story between the gangster red bean and the other three gangster Wangbao, red bean and mung bean.

Laughing is judged guilty of murdering gang lord Michael So and is sentenced to life imprisonment. Locked up behind bars, he meets the seemingly benign inmate Fok Tin Yam, a university professor in criminal psychology who is jailed for drug possession. Highly intelligent and manipulative, Fok reveals the power of his mind games by effortlessly subduing the violent prison bully. He also deduces that Laughing is sent to the prison on an undercover mission to find out the rogue cops within the police force. The clues lead him to inmate Chit, a former sergeant from the Narcotics Bureau who has been suffering from a mental disorder. To unlock the critical information from the deranged man, Laughing must get the help of Fok, but this enigmatic figure has an agenda of his own...

When Inspector Ma and his team raid an occult ceremony and successfully thwart a child sacrifice, the witch places a curse on his family. Years later, the wheelchair-bound Ma and his family begin to suffer the consequences, as his young daughter becomes a target of the witch's wrath.