Zhang Zhiqiang suffers from Alzheimer's disease. Because her work is busy, his daughter Zhang Li hires a nanny, Niu Cuihua, to take care of him. Niu Cuihua is courteous on the surface, but actually insidious and cunning. She colludes with her lover Lao Wu to abuse the elderly, misappropriate property, and forge a house gift agreement over a long period. During multiple visits, Zhang Li notices anomalies, and ultimately brings the two to justice through installing surveillance, collecting evidence, and setting a trap to lure the snake out of its hole, while resigning from her high-paying job to personally accompany her father through his remaining years.