Helen and Jackson are a couple navigating life together in the vibrant city of New York. Their journey takes a significant turn as they decide to visit Jackson's ancestral home, the Kilronan farmhouse in Kentucky, primarily to introduce Helen to his mother, Martha. This pivotal trip sets off a chain of events that will forever alter their lives.
Upon their return to the bustling city, Helen discovers she is pregnant, leading to a romantic proposal from Jackson, which she joyfully accepts. The couple exchanges vows at Kilronan, where Helen also encounters Jackson's paternal grandmother, Alice, who harbors suspicions about Martha's intentions.
Once they return to their New York apartment, a traumatic incident occurs—an assailant violently assaults Helen, robbing her of a cherished locket and inflicting a harrowing injury. Fortunately, there’s no harm to her unborn child. Meanwhile, Martha expresses her desire to sell Kilronan, asserting her inability to manage it alone. This leads Helen to propose a year-long stay at the farmhouse with Martha to assist in its renovation, much to Jackson’s initial dismay.
Jackson shares a haunting secret about his past, revealing that he feels responsible for his father's death at Kilronan when he was just seven. He confides in Helen about the trauma of that experience, including a complicated history involving infidelity. Driven by love, Helen believes a return to the farmhouse will help Jackson confront his "old ghosts."
As they settle in with Martha, the tension mounts. Helen grows increasingly wary of Martha, who seems intent on creating distance between her and Jackson. In her search for understanding, Helen speaks with Alice, who challenges Jackson's narrative about his father's demise, shedding light on a tragic accident rather than a fault of his own.
Feeling the strain of Martha's manipulations, Helen confides in Jackson, urging him to stand against his mother’s divisive tactics. However, that night, Martha's sinister nature reveals itself when she subtly administers pitocin, inducing Helen's labor. Waking in a daze, Helen finds herself in a nursery prepared by Martha, realizing the depths of her mother-in-law’s control.
As the drama escalates, Helen finds herself trying to escape Martha's grasp while on the verge of giving birth. An intense struggle ensues, revealing Martha's true colors as she seeks to manipulate events to her advantage, declaring herself the baby's true mother while attempting to silence Helen's cries for help.
Throughout the turmoil, Jackson remains oblivious to the full extent of his mother's malevolence until Helen finally breaks the silence, revealing the painful truths about his father's death and Martha’s deceit. It is disclosed that the supposed infidelity was a cover for Martha's own betrayal, a revelation that shakes Jackson to his core.
In a climactic confrontation, Jackson stands firm against Martha, vowing never to see her again, while Helen fiercely defends her family's newfound bond. The visceral nature of Helen and Jackson's struggle culminates in a powerful moment of liberation as they decide to leave Martha behind, embracing their future together with their newborn.
In the closing scenes, the couple pays a visit to Alice, introducing her to her great-grandson, a poignant closure to their harrowing tale—a symbol of hope as they begin a new chapter, free from the shadows of the past.
