In the 60s in Korea, the piano teacher Mr. Kim works in a factory giving music classes to the workers. When he receives a love letter from the student Miss Kwak, he delivers the letter to the supervisor and the worker is suspended for three days. Mr. Kim is a family man, married with two children, the girl Ae-Soon and the boy Chang-Soon, and he has just built and moved to a bigger house of his own. His wife Mrs. Kim also works too much at a sewing machine and they need a housemaid to help her in the housework. Mr. Kim asks Kwak's best friend, Miss Kyung Hee Cho, who is his private student of piano, to help him to find a housemaid. Miss Cho invites an unstable and unbalanced young woman to work for Mr. and Mrs. Kim and she introduces the housemaid to the family. Mr. Kim hires the youth and brings her to the household. But soon she behaves in a strange way, snooping Mr. Kim's private classes until the night that she seduces Mr. Kim and they have intercourse. The housemaid gets pregnant and uses her condition to press Mr. Kim. When she provokes a miscarriage, she blackmails Mr. Kim leading to the family's destruction.