Unable to find a suitable apartment in Seattle, Washington, journalist Nick Elliot drives to the suburbs, where he sees a sign advertising an available guest house belonging to frequent business travelers Liv and Cliff Forrester. After quickly accepting the property, he begins work renovating, and his presence attracts the attention of the Forresters’ fourteen-year-old daughter, Darian. On his first day as a writer at Pique magazine, Nick is chastised for showing up late and assigned to work on a dead-end story. One night, Darian visits Nick in the guesthouse and flirtatiously asks questions about his investigation. She returns the next morning while Nick is in the shower to give him a gift and invites him to her parents’ party later that week. Nick reluctantly attends the celebration and, feeling out of place among the high-society guests, seeks out Darian. She reveals she sneaked into the guesthouse and rewrote the article that earned praise from Nick’s boss. At her insistence, Nick takes Darian to a coastal lighthouse and forgives her for the intrusion. The girl explains she struggles to make friends because she was forced to skip grades in school. She kisses him, but he pulls away and insists they return home. Although Nick becomes distracted by Darian’s constant looming presence, he strikes up a friendship with his co-worker, Amy Maddik. During a barbeque one weekend, Amy becomes concerned about Darian’s obvious “crush” on Nick. After receiving a cryptic telephone call from Darian, Nick searches for her inside the main house. In her room, he finds a heart-shaped pillow embroidered with his and Darian’s initials, and hides in the closet while she undresses for a shower, unaware that Darian knows he is watching her. On his way out, he runs into Cliff, who asks him to help carry some boxes to the attic. There, Cliff shows off the carnival carousel he has reconstructed as a childhood toy for Darian. One afternoon, Nick attempts to tell Darian they can only be friends, but she reminds him of his previous voyeurism. Later, Nick confronts the Forresters about the suspicion that Darian vandalized his car, but the girl denies responsibility. Afterward, Darian’s only friend, Cheyenne, asks to speak with Nick after her horse riding lesson. Suspicious, Darian improperly mounts Cheyenne’s saddle, causing her to fall and break her arm. While preparing an important work presentation, Nick realizes his computer files have been erased and discovers a secret room in the garage that contains a candle-lit shrine Darian built for him. Vigorously attempting to rewrite his work, Nick ignores Darian’s dozens of telephone calls and has his locks replaced. He makes arrangements to move, but the landlady informs him the new property will not be available until the following week. As his relationship with Amy turns romantic, the woman dismisses Darian for asking questions about their sex life. Later, Darian locks Amy inside her private darkroom and fills the ventilation fans with wasps, sending her to the hospital. At her horse riding competition, Darian gloats to Cheyenne that Amy’s accident brought her closer to Nick. Afterward, she barges in on a fundraiser for Pique magazine and causes a disturbance by pretending to be Nick’s bitter girlfriend. Nick’s luck worsens when he discovers that Darian has sabotaged his new apartment lease by telling the landlady he is a drug dealer. Upon arriving home, he is arrested for sexually assaulting a minor. Darian tells police he beat her, and the interrogating officer informs Nick they have evidence she was raped. Nick theorizes that Darian orchestrated the claim by stealing a used condom from his trash bin. Before he can be formally charged, Nick returns home and packs to leave. Suddenly, Cheyenne arrives and tells Nick about Rick, a camp counselor Darian poisoned after he rejected her romantic advances. After Cheyenne leaves, she sneaks into the main house. Hearing music from across the yard, Nick crosses the property in search of Cheyenne. He ascends to Darian’s room, decorated with another shrine and a note reading, “Please forgive me.” Darian attacks him with a gardening tool and pushes him over the balcony. Moments before she can kill him, however, Darian’s parents arrive home, and the girl flees to the attic. Nick revives and slowly follows, finding Cheyenne tied to the carousel. Darian jumps from the shadows and again attacks Nick, screaming until Cliff reaches them. Darian knocks her father unconscious and Nick punches her in the face, sending her flying across the room. Sometime later, Nick moves into a new apartment with Amy, and Darian writes him apologetic letters from a mental institution, where she has developed a new crush on her sympathetic doctor.