Leah Garr, Meredith Baxter, is a driven, high-powered professional whose demanding job often pulls her away from home in Phoenix, Arizona. The distance and tension at home take their toll on her marriage to Marcus Garr, Tom Amandes, a devoted partner who yearns for more time with his family. Their 12-year-old daughter Robin, Evan Rachel Wood, feels the strain of constant arguments and decides that a summer apart could give everyone a chance to breathe. Robin asks to go to a summer camp, seeking a break from the daily friction and hoping for some space to sort out the tangled emotions at home.
At the camp, Robin forms a tentative friendship with Amelia McIntyre, Katie Booze-Mooney, an enigmatic girl whose life at home is shadowed by an abusive and controlling mother. The two girls share a quiet bond, and Amelia’s presence adds a layer of mystery to the camp experience. One night, drawn by a mix of curiosity and misadventure, Robin convinces Amelia to accompany her for a late swim in a nearby lake. Amelia, who is not a strong swimmer, struggles in the water and tragically drowns, an event that leaves Robin overwhelmed with guilt and a heavy, unshakable sense of responsibility.
Meanwhile, Leah makes a career move that reshapes the family’s plans. She accepts a major promotion that requires her to relocate to Denver, a change that means she will only be able to visit her husband and daughter on weekends. The prospect of losing daily contact with her family weighs on Leah, and she faces the challenge of balancing ambition with the needs of the people she loves most.
Back in the neighborhood, a new and seemingly friendly presence enters Robin’s life. Dorothy Cotton, Diana Scarwid, appears as a helpful neighbor who gradually becomes a fixture in the Garr household. In Leah’s absence, Dorothy ingratiates herself by offering to help look after Robin when Marcus is tied up with work or other obligations. Leah remains wary, sensing that something about Dorothy feels off, but Marcus reassures his wife that Dorothy is simply trying to be a good neighbor and friend.
Dorothy’s influence grows as she encourages open conversations with Robin. The girl confides in Dorothy, revealing that she blames herself for Amelia’s death at the camp. Dorothy responds with stories about her own past, suggesting that her younger sister was named Amelia and that she died in a childhood accident—a tale meant to comfort but that also deepens the eerie atmosphere around Dorothy. The sense that something isn’t right starts to seep into Robin’s days, and her unease grows as Dorothy’s behavior becomes increasingly intense and controlling.
As Dorothy’s attachment to the family intensifies, her conduct takes on a more obsessive edge. She begins lurking in Robin’s life in small, unsettling ways: following the girl’s activities, rearranging her bedroom, and scolding her when she doesn’t follow Dorothy’s exact instructions. These episodes are unsettling enough to alarm Marcus, who initially believes the concerns are exaggerated. He tells Leah that maybe Robin is overreacting, but the underlying tension between the family and Dorothy continues to build.
Unseen by the Garrs, Dorothy has a secret life she’s been preserving through a hidden channel of surveillance. She has been listening in on the Garrs’ conversations using a baby monitor she placed in Robin’s room, allowing her to hear every word and to manipulate situations from behind the scenes. This quiet intrusion deepens the sense of danger around Dorothy and fuels Robin’s paranoia, even as Marcus tries to rationalize the neighbor’s seemingly helpful presence.
The situation reaches a breaking point when Marcus and Leah travel out of town and leave Dorothy to supervise Robin alone. Dorothy’s overbearing conduct escalates, and when Robin tries to call her mother to vent or seek help, Dorothy strikes with brutal anger, knocking Robin unconscious. The parents return to a shocking scene: their daughter is missing, and blood marks the doorframe serve as a grim clue that something has gone terribly wrong. The couple, in a panic, enlist the help of their landlord to gain access to Dorothy’s apartment, where they uncover a troubling accumulation of photographs of Amelia—the deceased girl Robin had become entangled with at the camp.
The discovery reveals that Dorothy has been lying about her identity. The pieces fit together to reveal that she is the mother of Robin’s deceased friend, a girl who shared a name with Dorothy’s own late sister. The truth is even more chilling: Dorothy has been living under the name Dorothy Cotton, but her real name is Gretchen McIntyre. The confrontation with this hidden truth marks a turning point in the family’s ordeal as they piece together Dorothy’s true motives and history.
In a tense and dramatic moment, Robin is found to be held in Amelia’s former bedroom, now under Dorothy’s delusional belief that Robin is her daughter Amelia. The truth comes to a head when Marcus and Leah race to Gretchen’s address, determined to rescue their daughter before Dorothy can carry out any further harm. They arrive just in time to intervene as Gretchen, in a state of mental breakdown, attempts to brand Robin with a hot iron as punishment for disobedience. The arrival of the police soon follows, and Gretchen is taken into custody, her plan foiled and her grip on reality exposed.
With Gretchen’s arrest and the threat averted, the Garr family begins the slow process of healing. They return home to Phoenix with a renewed sense of commitment to one another. Leah makes a pivotal decision about her career, choosing to leave her Denver post and relocate back to Phoenix so she can be more present for her husband and child. The choice brings relief and happiness to Marcus and Robin, who are reunited with a more balanced, shared life and a safer, more stable home environment. The ordeal leaves the family with a clearer sense of what matters most: time together, trust, and the strength to confront danger when it appears, even in the guise of a neighbor who seemed to promise help but hid something far darker.
