Narcotics Chief Inspector Li Zhenbang (played by Nick Cheung) and undercover police officer Jiang Ming (played by William Chan) secretly carry out a plan to hunt down drug dealers, but they encounter danger. Jiang Ming is forced to walk the line between black and white and gradually loses control. In order to stick to the bottom line, former teammates have murderous intentions against each other. Suspicion, anger, madness, disappointment... All of them have lost their minds and are on the verge of collapse!