A young couple enjoying a peaceful day on the beach become the target of a lurking man hidden in the dunes. When the woman, seeking fuel for their fire, sends her partner away, the unseen assailant seizes the opportunity to attack. He brutally slashes her throat with a razor, and before her partner can return, he is ambushed from behind, strangled with wire until he is nearly decapitated.
Time passes, and we find the perpetrator, Frank Zito (played by Joe Spinell), waking up in terror in his cluttered one-room apartment adorned with strange artwork and creepy mannequins. Among his unsettling collection, one mannequin bears the clothes and bloody scalp of his beach victim. Frank examines old scars on his chest, dressing in a heavy coat before stepping out into the frigid New York City night.
As he traverses downtown Manhattan, he encounters two prostitutes outside a dilapidated hotel. Frank checks into a room, where he asks one woman if she has ever modeled and directs her to pose like the models in magazines. After a brief flirtation, he turns violent, choking her to death before gruesomely scalping her—a chaotic spiral of sickness and tears follows as he questions, "why did you make me do that?"
Returning to his dingy apartment, Frank nonchalantly tells a tenant he is "Christmas shopping" as he hauls in a new mannequin. Back in his space, he gets to work, attaching the bloody scalp to the mannequin’s head while hearing voices in his mind asserting that the beauty of women invites death. He then fixates on a newspaper headline about the earlier beach murders.
Frank prepares for another night of violence, dressing like a hunter and arming himself with a shotgun. Driving through the dark streets of Brooklyn and Queens, he spots a couple at a local disco. As they pause in their car to embrace, Frank makes his move, brutally shooting the man in an explosive act of violence, then shifting his fury onto the woman.
Later, in his room, he creates yet another mannequin resembling his latest victim while watching a news report on the recent double homicide. Conversing with his silent companions, he talks about stopping beautiful women, growing increasingly disturbed amidst his collection of trophies.
The proceedings take a twist when Frank notices Anna D'Antoni (Caroline Munro) while wandering in Central Park. After some stalking, he manages to engage Anna in a conversation about her photography. After an intimate dinner, Anna invites him to her art gallery show, stirring emotions within Frank that seem to clash with his murderous impulses.
In the coming days, Frank discovers Anna’s connections to her models, growing increasingly jealous and possessive. When he steals a necklace from Rita (Rita Montone), one of Anna's models, it leads to another horrifying encounter where he captures and kills Rita, adding her as the latest addition to his grim collection of mannequins.
As Frank continues to weave himself into Anna’s life, he grows desperate to ensure her attention remains solely on him. After attending Rita’s funeral under the guise of support, he faces a series of hallucinations that reveal the deep-seated trauma from his past. His troubled relationship with his mother's memory mingles grotesquely with his compulsions, causing him to lash out violently.
One fateful day in a cemetery, after an intense confrontation with Anna, Frank's tortured psyche is laid bare as he hallucinates being confronted by the undead figure of his mother. In this moment of mental breakdown, he returns home to face a horrific outcome wherein his mannequins morph into vengeful apparitions, leading to a truly grotesque climax.
The story culminates with the arrival of police officers at Frank's dim apartment, summoned likely by Anna's concern. They discover his lifeless body, seemingly a tragic end to his sordid and tormented existence. But as they leave, a hint of uncertainty lingers in the air; Frank's eyes flicker open, teasing a continuation of his dark story.
