Suffering from the effects of postpartum depression, former preschool teacher Sara Davis and her veterinarian husband Alex decide to relocate to a serene countryside farmhouse with their fussy newborn son, Liam. Their plans for tranquility take a dark turn when their realtor, Cindy, reveals the chilling history of the house: forty years ago, Anna Solomon tragically murdered her infant and her abusive father, Robert, before taking her own life within the same walls.
Intrigued by this haunting past, Sara discovers a striking resemblance between herself and Anna, leading her down a path of unsettling experiences. She begins donning belongings that belonged to Anna, which trigger eerie visions of Anna and Robert that ignite fears simmering within her. Strange sounds echo through the house, and everyday items mysteriously vanish. Meanwhile, Alex is preoccupied with understanding why local farmer Harrington is dealing with a sickly litter of pigs.
As the couple navigates their unsettling new life, they encounter their peculiar neighbor, Chris Renner. Over time, Sara uncovers that Renner is actually Anna's undisclosed brother, who shares a tragic story about their mother dying during childbirth, leading to Robert’s horrifying abuse. Renner confides that Anna had two other children, yet he remains tight-lipped about their fates and warns Sara against drawing further from the childlike voices that whisper from the hidden corners of the house.
Concerned for Sara's well-being and its potential impact on their son, Alex insists that she see psychiatrist Dr. Carver. Although Carver prescribes anti-psychotic medication, Sara resists, fearing it might compromise the deep bond she fosters with Liam through breastfeeding. The situation intensifies when Robert Solomon's ghost seems to attack Sara during bath time with Liam, leading to a harrowing moment when the baby suddenly vanishes.
After recovering from a near-drowning, Sara instinctively follows Liam's cries to the attic. There, she discovers a collection of the missing items laid before an impenetrable slab. In a shocking twist, two feral boys, representing Anna’s other children, appear, asserting that Liam belongs to them due to Anna's inability to care for him. The encounter grows threatening as one boy raises a hand ax, poised to swing it down onto Sara.
In a startling cut, the scene shifts to find Sara safely holding Liam in the now empty attic, her face alight with joy as she proclaims, > “He’s mine.” As Alex returns home, Sara confidently reassures him, “It’s over.” The couple embarks on a hopeful journey of family life, raising Liam together. However, a shadow of uncertainty crosses Sara's face once more as she grapples with the reality of impending motherhood, expecting for a second time.
