Four Flies on Grey Velvet

A drummer in a rock band who becomes the target of a stalker and unreliable accusations of murder. He hires a private investigator to uncover the tormentor and wrestle with fear, guilt, and suspicion. The escalating danger forces him to confront the possibility that his nightmare world may be closer to reality than he realizes.

Roberto's wife who harbors a dark secret and a cruel motive rooted in a traumatic past. She becomes entangled in the stalking plot and ultimately reveals herself as the killer, enacting revenge through violence. Her past abuse and complex emotions drive the climactic confrontation.

Nina's cousin who stays with the couple and begins an affair with Roberto. She becomes a suspect as tension rises and is eventually killed by the unseen assailant. Dalia's presence intensifies the love-triangle dynamics and heightens the sense of danger.

A beatnik artist friend of Roberto who offers guidance and predicts the killer's arrival. He provides a pragmatic, perceptive counterpoint to the paranoia in the house and helps push Roberto toward decisive action. His involvement frames the plot's cerebral, almost meta-fictional tone.

A flamboyant private investigator hired by Roberto to identify the tormentor. His pursuit leads him into a dangerous confrontation, and he is murdered with a poison-filled syringe, underscoring the peril of truth-seeking in this thriller. He embodies the film's theatrical, stylized detective archetype.

The live-in maid who overhears conversations between Roberto and Nina and becomes a casualty of the killer's reach in the park. Amelia's murder escalates the sense of inevitability and danger surrounding the household. Her presence marks the intrusion of outside violence into the couple's private life.

An unseen, chilling figure who stalks Roberto and orchestrates fear through photographs and threats. The killer's identity remains concealed for most of the film, amplifying suspense and the sense that danger hides behind familiar faces. The character embodies the cinema's archetype of the faceless menace.