On a rainy night, the Hong Kong Forensic Center was robbed by a group of well-trained bandits. The intruders held two forensic doctors, Chen Jiahao (played by Nick Cheung) and Qiao Lin (played by Yang Zi), hostage, and forced them to find a special corpse and a bullet in the corpse. During the autopsy, the forensic doctor discovered that the bullet was related to a major gang fight, and the identity of the bandit leader SANTA (played by Richie Jen) was also strange. In order to protect the evidence and uncover the truth, the unarmed Chen Jiahao and Qiao Lin used all the available equipment around them and the special terrain of the Forensic Center to plan a counterattack. The gradually enraged bandits became more and more manic and bloodthirsty. The forensic doctors who were in desperate situation were not afraid of the crisis of building destruction and death, and were determined to fight to the end!