As Lisa steps off her flight from Montreal to New York City, she's immediately overwhelmed by a gnawing anxiety. The source of her distress is a man whose piercing gaze seems to burrow into her very soul, tracking her every moment at the airport. To safeguard her illicit cargo—a stash of heroin cleverly hidden within an antique doll—Lisa discreetly hands it over to Sam Hendrix, a professional photographer whom she hopes will keep it safe. However, before she can even feel a sense of relief, the man’s rough grip ensnares her, forcibly dragging her away, leaving the fate of the doll hanging precariously in the balance.
Days later, con artists Mike Talman and Carlino mistakenly arrive at the apartment of Sam and his wife, Susy, thinking they are entangled with their intended target. Unbeknownst to them, they’ve entered a dangerous web spun by Harry Roat, the sinister figure who had been stalking Lisa. When Mike and Carlino accidentally stumble upon Lisa's lifeless body in Susy's apartment, they are coerced into assisting Roat with disposing of the corpse while simultaneously searching for the hidden doll.
As Sam embarks on a photography assignment, the trio of conmen launches into their elaborate scheme, cunningly exploiting Susy's blindness to pull off their sinister plans. They disguise themselves as various individuals, weaving a tangled web of deception that ensnares Susy, who unwittingly aids them in their quest for the doll. The deception proves effective, ensnaring even Susy, who, despite her blindness, starts to get pulled deeper into their plots.
At the same time, a young girl named Gloria, residing upstairs, innocently sneaks into Susy's apartment to return the borrowed doll. Her seemingly benign action triggers a series of events as she shares the grim news of Lisa's fate with Susy. Realizing the true intentions of the trio, Susy cleverly hides the doll at Sam's photography studio and instructs Gloria to wait for her husband at the bus station.
As Roat and his accomplices depart, they leave behind a convoluted trail of deceit and betrayal. However, Susy, now acutely aware of their nefarious game, prepares to defend herself by shattering every lightbulb in her apartment except for one—a safelight that signifies her resolve to outwit these cunning thieves. When Mike returns, he confronts a defiant Susy who refuses to hand over the doll. In a heated exchange, Mike orders Carlino to eliminate Roat, but fate interjects. Anticipating their scheme, Roat turns the tables by killing Carlino before setting his sights on Mike, who meets a swift end on Susy's doorstep. The tense game of cat and mouse escalates to a deadly climax.
As Roat escalates his threats, he begins to employ blackmail tactics, threatening Susy with the destruction of her home if she does not yield the coveted doll. In a moment of bravery, Susy unleashes a chemical agent, enveloping Roat in darkness, while simultaneously plunging the room into eerie silence by cutting off the safelight’s power. Although temporarily blind and confused, Roat resorts to using matches to light his path. Yet, Susy cleverly extinguishes the flames with gasoline, forcing Roat to rethink his strategy. Undaunted, Roat devises a makeshift light by opening the refrigerator door, casting an icy glow over the scene.
Seizing the opportunity, Susy retrieves the doll from its hiding place and reluctantly hands it to Roat’s greedy grasp, all the while preparing for a counterstrike with a kitchen knife as Roat becomes captivated by his prize. In a swift, calculated move, Susy manages to strike Roat down, seizing the moment to flee.
However, her escape route is thwarted when she discovers that the front door is locked with an unyielding chain. Refusing to give in, Susy turns her attention to the kitchen window when suddenly, Roat lunges at her, clutching her ankle in desperation. She narrowly escapes his grasp, seeking cover behind the refrigerator just as he readies to deliver her demise.
As the suspense peaks, the sound of sirens pierces through the apartment, signaling the imminent arrival of Sam and Gloria, accompanied by the police. In this tense moment, they uncover a shaken yet unharmed Susy crouching behind the refrigerator door, while the sinister Roat lies motionless nearby, a grim testament to her intelligence and resilience in the face of overwhelming danger.
