Shock

Dora's first husband Carlo—an abusive heroin addict—was thought to have committed suicide at sea after his boat was found adrift. Dora's pregnancy with Marco and the ensuing events led to a nervous breakdown and her institutionalization with electroshock therapy. This tragedy shapes Dora's memories and fuels the fear that Carlo may haunt the house.

Bruno and Dora move back into the house where Dora once lived with Carlo. Bruno is away on flights as a commercial airline pilot, leaving Dora to manage Marco on her own. The move reopens old memories and sets the stage for the house's disturbing atmosphere.

Marco begins to exhibit unsettling changes in personality and is inexplicably drawn to the basement. He shreds Dora's underwear, an act that alarms his mother and hints at a malevolent force in the home. Dora grows increasingly wary of the house and her son's behavior.

Dora finds a bundle of roses with a note addressed to her from Carlo, triggering fear and confusion. She confronts Marco, who denies writing the message, and slaps him in disbelief. The incident deepens her conviction that Carlo's presence is targeting Marco.

Dora brings Marco to her psychologist friend, Aldo Spidini, for examination. Aldo suggests that Dora's trauma from Carlo could be projecting onto Marco, though Dora confesses she feels Marco is being haunted by his deceased father. The session highlights the tension between memory, perception, and possible possession.

The piano begins playing by itself and Marco's room drawings levitate, yet Marco is nowhere to be found. Dora eventually discovers him in the den, asking why she killed his father. The encounter triggers a repressed memory of Dora's act of slitting Carlo's throat after he forced heroin and LSD on her.

Dora recalls the memory of killing Carlo and realizes the haunting may be rooted in her past rather than mere possession. Bruno tries to reassure her that Carlo killed himself, trying to keep the truth at bay. Despite his assurances, Dora remains convinced Carlo is haunting the house and manipulating Marco.

One night, Dora wakes to banging in the basement and finds Bruno smashing through a brick wall. Behind it lies Carlo's corpse, which Bruno reveals he had hidden seven years ago, having murdered Carlo and staged his disappearance as a suicide. He explains they returned to the house to avoid discovery and to finish moving the remains.

In a furious rage, Dora attacks Bruno with a pickaxe and mortally wounds him, then stuffs his body behind the wall beside Carlo's corpse. The act exposes the couple's crime and intensifies the house's supernatural secret. Dora's actions seal her fate as both killer and haunted mother.

Dora climbs upstairs only to encounter a ghastly apparition of Carlo lying in Marco's bed, and Marco himself runs toward Dora only to transform into Carlo. Dora screams in terror as the boy's body seems possessed by his father's ghost. The haunting becomes personal and terrifying as Carlo's presence asserts itself.

Dora tries to flee the house, but violent poltergeist activity blocks her exit. She returns to the basement as furniture shifts toward her, culminating in a desperate act: she slashes her own throat with a boxcutter while Carlo's hand appears to guide the knife. The household's supernatural violence reaches a brutal climax.

Outside in the backyard, Marco sits at a table drinking tea with his father's invisible ghost and then pushes the specter on a tree swing. The scene shows Carlo's memory continuing to inhabit the home through Marco. The haunting ends with the boy accompanied by his father's ghost.