Because of some transfer arrangement and several complicated cases, AICIP Au Yeung Chung (Bobby Au Yeung) and CUSP Tsui Hay-yi (Joey Meng) become collaborating partners. The duo have mutual understanding. Sheung Siu (Jeannie Chan), daughter of a logistics company boss, hates Au Yeung Chung as she is certain that he has caused her family to break up. Au Yeung Chung had promised the late Mrs. Sheung he would be tolerant of Sheung Siu. But he realizes Sheung Siu has hooked up with lawyer Tai Ching-kwan (Joe Ma) and gang boss Tai Ching-yan (Pierre Ngo). He also finds out his colleague and also buddy Chun Wing-hei (Mat Yeung) used to go out with Sheung Siu. The duo keep a close watch on the Tai brothers as they want to get her back on the straight and narrow. Au Yeung Chung and Ching-kwan have different values. Also, they each have their own interpretation of justice. A battle of wits is quietly triggered when these two guys run into each other.
