Fashion model Valentina (Susan Scott) agrees to help her journalist boyfriend Giò Baldi (Simón Andreu) research the effects of LSD. While under the influence of the drug, Valentina sees a man bludgeon a woman to death with a spiked gauntlet. Baldi publishes a report of her hallucinations; however, Valentina believes what she has seen is real. She begins to realise that the killer is stalking her, although neither Baldi nor the police will believe what she tells them