Longpan City Criminal Police Captain Lin Tao and Qin Ming chief of the forensic department, have been old friends for many years. Qin Ming's assistant reported resignation because he could not bear Qin Ming's weird temper. Li Dabao of the Trace Inspection Division was seconded to join the working group. At the beginning, Qin Ming didn't trust Dabao, who was a girl, but the stubborn Dabao showed quite good reasoning and observation abilities in solving the case, and his sense of smell was extremely sensitive. The picky Qin Ming decided to keep Dabao. The Iron Triangle of Longpan Police Department has also been formed. They cooperated with each other and solved all kinds of incredible cases one after another.