Hoi (Deric Wan) was once a cop, but his hot temper cost him his job. He then joined a security company as the head investigator. Ching (Ng Kai Wah), Hoi’s partner in the police force, on the other hand, was always cool-minded. Though Hoi had left the force, he still worked closely with Ching and they solved many tough cases like “Killing with Arrows”, “Vanishing Art Director”, “Corpse in the Sack” and “Homicide in a Sealed Room”. Then, the two friends fell for the charming Sai (Jessica Hester Hsuan) together. Sai chose Ching after she broke up with Hoi. Hoi went back to his ex-girlfriend Man (Mok Ho Yan), but he was immediately caught up in the case “Poisonous Wedding”. Man was murdered at the wedding and Sai and Hoi were suspects….