Hae-won is a wife who is pathologically obsessed with her husband. When her husband, In-seong, goes to work or is out of her sight, she constantly calls him and monitors his every move. One day, Hae-won invited her best friend, Song-joo, to their house to hang out, but she began to suspect that the relationship between Song-ju and In-seong was strange, and ends up threatening her best friend's life when she comes to clear up her misunderstanding.