When applying for a job as a tutor for the Lu family, the top wealthy family in Beijing, Yan Zhen thought that his life was about to start a win-win mode. The annual salary is seven figures, food and accommodation are included, and the employer's family is extremely handsome. Most importantly, her student, the young master of the Lu family, is a well-behaved and cute child like an angel. Until the first night she checked in, the young master hugged the pillow and knocked on her door with tears in his eyes: "Teacher, someone is crying in the wall of my room." Yan Zhen:? She soon discovered that strange things happened frequently in this gorgeous villa: the sound of marbles often coming from the empty house, nursery rhymes that played automatically late at night, and the ferocious black shadows that the young master repeatedly painted on the paintings... The whole family was talking about it, asking the master today, and doing things tomorrow. Only Yan Zhen, a staunch materialist, silently opened her toolbox. "There's a cry in the wall? That's the water hammer effect of the pipeline." "The female ghost in white is floating by? That's the low ignition point of white phosphorus and the addition of a drone." "As for the young master's hallucination..." Yan Zhen adjusted his glasses, glanced at the Lu family members who had their own ulterior motives, and sneered at the corner of his mouth, "I'm afraid this is not science, but something that can be explained by criminal investigation." Everyone thought she was a fool who didn't understand the rules and would be kicked out sooner or later. Until she successfully reproduced the whole process of "ghost hanging" in front of everyone, using a fishing line and a pulley block. Everyone: "..." The second uncle of the Lu family, who had been watching with cold eyes, the rumored unkind business boss, handed her a cup of hot tea for the first time and asked in a low voice: "Teacher Yan, what else do you not know?