Leo Kroll, a lab technician with an unsettling obsession for maternal figures, hides a dark secret: he is a serial killer responsible for the gruesome murders of multiple nurses. His latest fixation revolves around Clara, the nurse who cared for his possessive mother during her hospitalization due to a heart attack. Kroll’s morbid fascination with dolls is reflected in his brutal acts, with an eerie doll appearing at each crime scene as a chilling signature. Nevertheless, it is his attachment to Tally, an employee at an amusement park who gifted him a doll, that hints at a flicker of humanity beneath his depraved disposition.
As the police delve into the investigation, Kroll’s agitation becomes palpable. His possessiveness and paranoia spiral out of control with every tick of the clock. Visits to his ailing mother serve to deepen his malevolence, culminating in her fatal heart attack that occurs right after he confesses to Clara's murder. The once jovial atmosphere of the amusement park transforms into a shadowy reminder of Kroll’s twisted desires.
Upon returning to the park, an encounter with Barbara, Tally’s coworker, sparks a catastrophic chain of events that would ultimately seal his fate. Kroll's desperation intensifies, and his urge to destroy overtakes his previous fixation with dolls. The shocking murder of Barbara, a seemingly innocent victim, further complicates the police investigation and raises the stakes.
With the death of his mother, Kroll is compelled to confront the true essence of his hatred for women. His proposal to Tally, although spurned, marks a critical shift in his already twisted psyche; her rejection plants seeds of doubt that allow his mother's venomous remarks to flourish, fuelling his dark instincts once again.
As the police intensify their pursuit of Kroll, they bug Tally's apartment in hopes of catching him in the act. However, when Kroll emerges from the shadows, determined to claim another victim, the police are taken by surprise. In a heart-pounding climax, they storm into the room, gunshots ringing out as Kroll leaps through the window to meet his end. The fate of Tally, now ensnared beneath the debris, remains precariously uncertain, leaving the audience with a haunting sense of ambiguity.
