Thirteen-year-old Tyler and his sixteen-year-old sister Shannon spot sixteen-year-old Walker Ranson walking down the street, and Shannon immediately becomes obsessed with the young man. Shannon decides to sneak after Walker, and Tyler follows. The siblings' grandma had died recently, and their grandma told Tyler to keep an eye on his sister. This is because his sister has supernatural powers and can predict the future. They follow Walker to his house, and Shannon ominously states that Walker is the one. Tyler doesn't know what she means by that. The two siblings return to their house, and Shannon becomes more obsessed with Walker. She constantly wonders what he is doing and even makes charms for the man. The following day, she declares that Walker is a night owl and the two siblings stalk his house at night. Shannon tries to open the gate to enter the backyard, but Walker hears a noise and steps outside. He asks if Alice or Mallory is there. Alice and Mallory are two girls that Walker is attracted to. However, Walker doesn't leave the porch of his house. The two siblings manage to avoid detection, and they sneak away. However, Shannon is upset that Walker would mention two other girls' names. Her obsessions grow, and Tyler reminisces about their grandmother. Their grandmother raised them, and their grandmother kept mysterious objects in the cellar. One day, when Tyler was nine, he entered the basement and discovered a female doll imprisoned in a glass doll. Spiders surrounded the doll, and yellow egg sacks hung from the doll's legs. He had no idea what that meant, but his grandmother repeatedly told him that he is Shannon's familiar. Once again, Tyler never truly understood what she meant. As Shannon's obsession grows, Tyler senses that their relationship has changed. Shannon confirms this when she reveals that she will stay at the house and that he will eventually leave. When Tyler says he never wants to go, Shannon reveals that he will be released from her service. Tyler doesn't understand what that means. Shannon then says that she knows who Alice and Mallory are. Mallory was a woman that Walker met at a bar. They had sex on their first date, and later Mallory ghosted him, leaving Walker heartbroken. Walker is currently attracted to Alice. However, Alice is not interested in Walker at all. Tyler assumes she gathered this information with her supernatural powers. Tyler hopes that Shannon will get over Walker, but two weeks later, her obsession escalates. Shannon reveals that she will go to Walker's house in the middle of the night as Walker is going out to dinner with Alice. The two go to Walker's house, and Shannon breaks into his house. Tyler is horrified when Shannon returns with Walker's dog. The two return home and Shannon keeps the dog in her room. Tyler has no idea what she's thinking and hopes she doesn't do any more crazy things. The following day, he goes to school. Shannon doesn't go to school. Throughout the day, Tyler's anxiety heightens, and when he returns to the house, he hears a noise in the cellar. He sneaks into the basement and sees a naked Walker tied up on the floor in a middle of a circle of chalk. A naked Shannon is above Walker. Tyler is horrified as Shannon spreads her legs and sucks Walker inside through her privates. As Walker is sucked into Shannon, her belly expands as if she is pregnant. Once Walker is entirely inside her, Shannon spots Tyler and tells him to get out. Tyler runs to his room, and Shannon later emerges from the cellar. She's visibly exhausted and reveals that Tyler has to leave the house as she will give birth to baby Walker. Tyler asks her where he would go and reveals that Shannon brought him into this world and that she should take him out. Shannon tells him that he must leave. Later that night, Tyler falls asleep in his bed. However, when he wakes up, Tyler is in a new town. Tyler believes Shannon is the cause for this and begins to walk down the street, hoping that somebody will adopt him.