After surviving a childhood plane crash that left her parents dead and her sister catatonic, Dr. Brigid Sullivan becomes a brilliant psychiatrist driven to understand the fractured mind. Years later, she takes on a new patient at a maximum-security hospital: Lily Diangelis, a beautiful but deeply disturbed woman who has spent over a decade in a catatonic state after murdering her own mother.
When Lily begins speaking only during their private sessions—and demonstrating an uncanny knowledge of Brigid’s past—Brigid finds herself drawn into a disturbing psychological entanglement. Lily claims that “voices” reveal intimate details about Brigid’s life, including secrets no one else could know. As their sessions intensify, the boundary between doctor and patient begins to dissolve.
Brigid soon experiences vivid dreams that seem to mirror Lily’s inner world—dreams that Lily later describes in chilling detail as if they were her own. As hallucinations bleed into waking life, Brigid’s grip on reality begins to falter. Her relationships suffer, and her professional judgment deteriorates as she becomes increasingly obsessed with understanding Lily.
When Brigid attempts to document their interactions, she discovers that Lily’s voice never appears on recordings, leaving her isolated and unsure whether the encounters are real or imagined. Meanwhile, violent fantasies begin to invade her consciousness—fantasies that are shockingly mirrored by real-world murders, including the brutal killing of her boyfriend.
As suspicion closes in and the body count rises, Brigid must confront the terrifying possibility that her connection to Lily is driving the violence—or that something far more insidious has taken root in her mind. When Lily escapes the confines of her illness long enough to commit another murder using Brigid’s own scalpel, the line between victim and perpetrator collapses completely.
Unable to trust her own perceptions and haunted by voices she can never silence, Brigid abandons her career and retreats into isolation. Years later, living alone in the Nevada desert, she maintains a fragile existence—no longer seeking answers, only control—while the whispering continues.