ORGASMO

American socialite Catherine West arrives in Italy from New York to a flurry of journalists following the car accident death of her husband Robert, a Texas oil baron who left her his $200 million estate. She retreats to an Italian villa rented by her austere lawyer, Brian Sanders. Catherine soon meets Peter Donovan, a young American man from Boston whose car has broken down nearby. Peter manages to manipulate his way into staying with Catherine, who is initially icy toward his romantic advances. However, Peter swiftly manages to seduce her, and the two engage in a passionate affair.

Catherine travels to London to visit with her late husband's relatives to discuss property she is bequeathing to them, but finds them to be abrasive and angry with her, believing she married Robert solely for his money. Late one night, Catherine senses someone has broken into the house, but the housekeeper Teresa attributes Catherine's paranoia to her abuse of alcohol and prescription drugs. When Catherine invites Peter to stay with her for a week, his sister Eva arrives at the villa unexpectedly. Catherine enjoys the siblings' companionship and youthful vivaciousness.

During a dinner meeting with Brian, Catherine admits she is suffering from liver failure due to her alcoholism. Upon returning to the villa, Catherine finds Peter and Eva in bed together nude. She presumes the two have engaged in incest, but Peter informs Catherine that he and Eva are not blood-related, and are in fact only stepsiblings. Eva confesses that she is sexually attracted to Catherine, and the three soon engage in a series of nightly debaucherous threesomes fueled by Peter and Eva's indulging of Catherine in liquor and stimulant drugs.

One night, Catherine, disgusted with herself and in a drunken rage, orders Peter and Eva to leave the villa. They oblige, but soon return, and begin physically abusing Catherine and taking control of the house, subduing Catherine by forcing her to drink. Finding herself held hostage by the siblings, Catherine becomes increasingly desperate to escape Peter and Eva. She manages to produce a gun, with which she shoots Peter. Catherine loses consciousness due to a sedative fed to her by Eva, and awakens to find that the gun was loaded with blanks by the siblings, and that Peter was unharmed. The two bind and gag Catherine, tying her to a bed. When Brian visits the villa, Peter tells him that Catherine has descended into a depression, and has threatened to commit suicide.

Locked in her upstairs bedroom, Catherine is further tormented by the siblings, who, on one occasion serve her a live toad for dinner. The two later bring her whiskey and a large number of barbiturates, along with a falsified letter stating Brian has died in a plane crash, with the hope that Catherine will voluntarily kill herself by overdosing. Catherine manages to escape her bedroom and flees to the attic, accessing the roof of the villa. Brian arrives, and witnesses Catherine collapse over the edge of the roof, falling to the veranda below and fracturing her skull. Brian picks the injured Catherine up in his arms. The two briefly make eye contact before he ruthlessly throws her over the veranda onto the driveway below, killing her. Brian, who has conspired with the siblings to steal Catherine's fortune, produces two forged suicide notes and orders Peter to alert authorities to Catherine's staged suicide. It is revealed that Brian is in fact Peter and Eva's uncle, and had Catherine unknowingly sign documents that bequeathed her estate to the trio.

After the reading of Catherine's last will and testament, Brian is met by a detective who notifies him that New York police discovered that the brakes in Robert's car were tampered with, causing his fatal road accident. Brian momentarily fears their plot has been discovered, until the detective states that police believe Catherine caused the accident, as Robert had planned to divorce her. Based on this conclusion, Catherine is not legally entitled to her husband's estate, which Brian is informed will instead go to his aunt. Meanwhile, as Peter and Eva gleefully drive through the city in their convertible, they are killed in a head-on collision with a truck.

Catherine is held captive and psychologically tormented by Peter and Eva, but ultimately manages to escape her confinement as Brian arrives at the villa.

The conclusion reinforces the film’s exploration of psychological fragility and the dangers lurking beneath surface glamour. Catherine’s ordeal at the hands of Peter and Eva is both a cautionary tale of trust and seduction and a showcase for Lenzi’s interest in moral ambiguity and shifting power. The ending suggests a return to agency for Catherine, but the trauma and instability she endures linger, leaving the final note unsettling rather than triumphant.