Late in night a sharp knife was pierced into the heart of an investor from other place by a mysterious killer, police had put all its efforts to solve the case without making any progress. From then on many dead bodies were left in street by the mysterious killer with a knife, and people in the city were scared by what they heard about the cases. Instructor FineElegance Li of the group of the criminal investigation of the municipal bureau of public security just joined the group to solve the case, but the sharp knife was pointing at his heart, through his own vigilance, courage and fight, he barely missed the knife, thus he could continue his investigation. At the same time he found there is(are) a mole(moles) inside the bureau... Under extremely difficult situation, he focused his attention on the cases as hard as he could, he persisted in his investigation despite various interference, in the end he found the identity of the killer, after a life or death fight, he caught the killer, exposed the evil and the corrupted behind the killer. The truth is really unbelievable...