The film follows Maddie Young, a deaf and mute writer portrayed by Kate Siegel, who resides in isolation within a remote woodland home. Maddie's hearing was taken from her at the tender age of 13 due to a severe case of bacterial meningitis, causing her to rely on American Sign Language (ASL) for communication. Living a solitary existence, she fills her days with the craft of writing while connecting with her sister Max and friend Sarah, both of whom engage with her through video calls.
As the story unfolds, Maddie grapples with writer's block, desperate to finish her latest novel which experiments with multiple conclusions. The quiet life she leads is disrupted one evening when Sarah visits to return a borrowed book. Following Sarah's departure, tranquility envelops Maddie until it is violently shattered by the shocking murder of her friend just outside her door. Oblivious to the tragedy occurring in the darkness, Maddie remains blissfully unaware of the lurking danger.
Realizing her disability, a masked attacker decides to prey on Maddie, initiating a horrifying game of cat and mouse. He savors the advantage of her silence, stealthily entering her home and stalking her in the shadows. Tension escalates as Maddie begins to sense an intruder's presence—first through vibrations and then by catching glimpses of him through her windows.
Employing her intellect and the layout of her surroundings, Maddie strategizes to protect herself. In a desperate move, she types on her laptop that she hasn't seen his face, aiming to convince him to spare her life. Unmoved, the killer reveals himself by removing his mask, showing a chilling lack of fear regarding identification. His objective is not to remain hidden but to instill terror and ultimately claim her life.
What ensues is a harrowing and violent clash between Maddie and her tormentor. She employs a range of tactics: activating her car alarm to signal for help, barricading herself, and even attempting to strike back with a crossbow she keeps for protection. Each endeavor is met with unique obstacles, highlighting Maddie's tenacity and resourcefulness, alongside the killer's cruel resolve.
In a defining moment, Maddie boldly scrawls a final message on her door with her own blood: "Do it," solidifying her acceptance of her dire situation while defiantly challenging the killer. This courageous act transforms her role from victim to determined survivor, igniting an unyielding will to fight back against her attacker.
In the film's climactic sequence, Maddie utilizes her heightened senses of sight and touch to gain the upper hand. After an intense struggle, she overcomes her assailant, leveraging her wit, the physical environment, and the crucial element of surprise. The film culminates with Maddie, severely injured but triumphant, as she sits on her porch awaiting the arrival of police officers—her survival a testament to her strength and resilience.
