Michael Tse as Laughing, Leung Siu Tong
Bosco Wong as Michael So
Kate Tsui as Paris Yiu
Fala Chen as Jodie Chow
Damien Lau as Harry Gung
Total Episodes: 30 episodes
Aired Dates: August 8 to September 16, 2011
Time Slot: Mondays to Fridays, 9.30pm
Channel: Astro Channel 921
Leung Siu Tong, Laughing, rejoins the police force after a stint as an undercover. His new task is to train the new recruits in the Criminal Intelligence Bureau and prepare them for future tasks as undercover agents.
Laughing gets to know So Sing Pak, Michael, who is a triad member. Although Michael is crippled and treated badly by his gang mates, he is actually very smart and calculative. He agrees to work with Laughing to be Laughing's informant. He plans to use Laughing as a stepping stone to climb higher in the triad ranks.
Michael has a love-hate relationship with Paris Yiu, a barrister. They were childhood friends and Michael funded Paris' law education.
Laughing initially has issues with his supervisor, Madam Jo, who coincidentally looks like his former girlfriend. As time passes, these two partners learn to appreciate each other more and eventually fall in love.
However, their relationship is tested over and over again as Laughing prefers working out of the system but Madam Jo is disciplined and adheres to the system.
Michael's ambition to be the triad leader takes him to the point of no return. He sacrificed one of Laughing's teammate and this incident forced Laughing to return once again as an undercover agent.