Hired to play piano at a secluded manor, Grace unintentionally overhears a brutal homicide committed by the mistress of the house and her clandestine lover. When the killers discover that her visual impairment is only partial, the ruthless conspirators administer a blinding toxic compound, robbing her of her remaining sight to silence her testimony. Terrified and isolated in total darkness, Grace struggles to piece together what she witnessed through sound alone.
Complications multiply when Ian Thorne, the kind-hearted brother of one of the murderers, rushes to protect Grace without understanding the blood on his sibling's hands. As secondary witnesses fall to brutal executions, the killers herd the remaining survivors into an abandoned industrial warehouse to recover missing extortion funds. Robbed of her sight, Grace must rely on her acute auditory senses to expose the culprits before she is eliminated.
