勇探高中正为了追捕“玫瑰连环杀手”。行动当日，儿子进星在街上巧遇正在埋伏的中正，中正为怕误了大事，把进星赶走，未料进星竟因此失踪，从此人间蒸发。妻子绮文因儿子失踪一事，决定和中正离婚。加上追捕杀手失败，遭上司怒斥他严重失职，中正受到连番打击，决离开警队。

Ko Chung Ching (Michael Miu), an ex-policeman, quit his job to set up a private investigation company two years ago, right after his son Tsun Sing went missing because of a slap while Miu was searching for the "Rose Killer". His subordinates include Man Kai Ching Super (Power Chan), Man Tai Po (Bernice Liu) and Lam Yan Yan (Vivien Yeo).Kenneth Ma plays the cop who takes on Miu's "Rose Killer" case. Ching works and carries on looking for Sing. He meets Lai Siu (Melissa Ng) the manager of a group of part-time actors. She learns by chance that she was involved in Sing's disappearance, and as such feels guilty, so agrees to help find Sing. She uncovers a few clues and finds out Sing's disappearance is connected to Sing's divorced wife and good friend Lau Kwok Wai (Wong Chi Yin). Ching is shocked by the truth...