Build a movie plot around this: What was inside the sack? A porcelain doll
A teenage girl, Su-mi, is being treated for shock and psychosis. The doctor questions her about the day that led her to be admitted, but she refuses to answer. Later, Su-mi is returned home to her family's secluded estate with her father and her younger sister Su-yeon. At a family dinner, their cold and distant stepmother announces that their uncle and his wife will arrive tomorrow night for a dinner party. The girls are disappointed with her announcement and leave the table. Whilst the family goes to sleep, Su-yeon hears strange noises in her bedroom and goes to Su-mi for protection. However, Su-mi experiences a terrifying nightmare in which a female ghost with blood pouring down her legs climbs on top of her bed. Afterwards, all of the females in the family discover that their periods have occurred at the same time.The next day, Su-mi finds several family photos, which reveal that her father and her stepmother once worked together and that the stepmother was an in-home nurse for her late biological mother. Su-mi discovers bruises on her sister's arms and angrily confronts her stepmother about it. At night, their uncle and his wife attend the dinner party and the stepmother tells bizarre stories, much to the bewilderment of the other guests. Suddenly, the uncle's wife suffers a violent seizure. Upon recovering, she claims to have seen a ghost beneath the kitchen sink. The stepmother later attempts to search for the ghost and she is attacked when a disfigured arm suddenly grabs her.After finding out that her pet bird has been killed, the stepmother enters Su-yeon's room and discovers another dead bird, along with defaced family photos of herself. She locks Su-yeon in the closet and promises to release her if she apologises. Su-mi eventually releases her sister and she tearfully apologises that she didn't hear her pleas in time. Su-mi's father blames her for the family's recent trauma, but she retorts that her stepmother is to blame for attacking Su-yeon. The father tells her that Su-yeon is dead, but Su-mi...